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Yan X, Sun M, Ji J, He Z, Zhang J, Sun W. Epitaxy of (11-22) AlN Films on a Sputtered Buffer Layer with Different Annealing Temperatures via Hydride Vapour Phase Epitaxy. MATERIALS (BASEL, SWITZERLAND) 2024; 17:327. [PMID: 38255495 PMCID: PMC10817662 DOI: 10.3390/ma17020327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 01/05/2024] [Accepted: 01/05/2024] [Indexed: 01/24/2024]
Abstract
AlN epilayers were grown on magnetron-sputtered (MS) (11-22) AlN buffers on m-plane sapphire substrates at 1450 °C via hydride vapour phase epitaxy (HVPE). The MS buffers were annealed at high temperatures of 1400-1600 °C. All the samples were characterised using X-ray diffraction, atomic force microscopy, scanning electron microscope and Raman spectrometry. The crystal quality of epilayers regrown by HVPE was improved significantly compared to that of the MS counterpart. With an increasing annealing temperature, the crystal quality of both MS buffers and AlN epilayers measured along [11-23] and [1-100] improved first and then decreased, maybe due to the decomposition of MS buffers, while the corresponding anisotropy along the two directions decreased first and then increased. The optimum quality of the AlN epilayer was obtained at the annealing temperature of around 1500 °C. In addition, it was found that the anisotropy for the epilayers decreased significantly compared to that of annealed MS buffers when the annealing temperature was below 1500 °C.
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Affiliation(s)
- Xuejun Yan
- Research Center for Optoelectronics Materials and Devices, School of Physical Science and Technology, Guangxi University, Nanning 530004, China; (X.Y.); (M.S.); (J.J.); (Z.H.)
| | - Maosong Sun
- Research Center for Optoelectronics Materials and Devices, School of Physical Science and Technology, Guangxi University, Nanning 530004, China; (X.Y.); (M.S.); (J.J.); (Z.H.)
- College of Mathematics and Physics, Beijing University of Chemical Technology, Beijing 100029, China
| | - Jianli Ji
- Research Center for Optoelectronics Materials and Devices, School of Physical Science and Technology, Guangxi University, Nanning 530004, China; (X.Y.); (M.S.); (J.J.); (Z.H.)
| | - Zhuokun He
- Research Center for Optoelectronics Materials and Devices, School of Physical Science and Technology, Guangxi University, Nanning 530004, China; (X.Y.); (M.S.); (J.J.); (Z.H.)
| | - Jicai Zhang
- Research Center for Optoelectronics Materials and Devices, School of Physical Science and Technology, Guangxi University, Nanning 530004, China; (X.Y.); (M.S.); (J.J.); (Z.H.)
- College of Mathematics and Physics, Beijing University of Chemical Technology, Beijing 100029, China
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Wenhong Sun
- Research Center for Optoelectronics Materials and Devices, School of Physical Science and Technology, Guangxi University, Nanning 530004, China; (X.Y.); (M.S.); (J.J.); (Z.H.)
- State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures, Nanning 530004, China
- Guangxi Key Laboratory of Processing for Nonferrous Metals and Featured Materials, Guangxi University, Nanning 530004, China
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Sub-nanometer mapping of strain-induced band structure variations in planar nanowire core-shell heterostructures. Nat Commun 2022; 13:4089. [PMID: 35835772 PMCID: PMC9283334 DOI: 10.1038/s41467-022-31778-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 07/01/2022] [Indexed: 11/22/2022] Open
Abstract
Strain relaxation mechanisms during epitaxial growth of core-shell nanostructures play a key role in determining their morphologies, crystal structure and properties. To unveil those mechanisms, we perform atomic-scale aberration-corrected scanning transmission electron microscopy studies on planar core-shell ZnSe@ZnTe nanowires on α-Al2O3 substrates. The core morphology affects the shell structure involving plane bending and the formation of low-angle polar boundaries. The origin of this phenomenon and its consequences on the electronic band structure are discussed. We further use monochromated valence electron energy-loss spectroscopy to obtain spatially resolved band-gap maps of the heterostructure with sub-nanometer spatial resolution. A decrease in band-gap energy at highly strained core-shell interfacial regions is found, along with a switch from direct to indirect band-gap. These findings represent an advance in the sub-nanometer-scale understanding of the interplay between structure and electronic properties associated with highly mismatched semiconductor heterostructures, especially with those related to the planar growth of heterostructured nanowire networks. Planar growth of nanowire arrays involves interactions between materials that affect the electronic behavior of the effective heterojunction. Here, authors show how core curvature and cross-section morphology affect shell growth, demonstrating how strain at the core-shell interface induces electronic band modulations in ZnSe@ZnTe nanowires.
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Yang J, Wang Y, Huang L, Li G, Qiu X, Zhang X, Sun W. High-Efficiency and Stable Perovskite Photodetectors with an F4-TCNQ-Modified Interface of NiO x and Perovskite Layers. J Phys Chem Lett 2022; 13:3904-3914. [PMID: 35471973 DOI: 10.1021/acs.jpclett.2c00860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Nickel oxide (NiOx), a typical p-type semiconductor, is emerging as the most promising hole transport layer material. However, the inferior interfacial contact of the NiOx/perovskite interface has limited the improvement of the performance of photodetectors (PDs). In this work, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ) is introduced to modify the NiOx/perovskite interface to prepare high-performance PDs. This study shows that the F4-TCNQ layer interacts with the NiOx/perovskite layers. It can increase the Ni3+/Ni2+ ratio and then enhance the hole extraction and charge carrier mobility; on the contrary, it can form a new Lewis adduct and passivate the undercoordinated Pb2+ ions. Furthermore, with the F4-TCNQ modification, the perovskite film exhibits good thermal stability and photostability. The PDs demonstrate excellent photoelectric properties and long-term stability in the atmosphere. This finding provides a simple and efficient way to further develop the NiOx/perovskite interface.
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Affiliation(s)
- Jia Yang
- Research Center for Optoelectronic Materials and Devices, School of Physical Science and Technology, Guangxi University, Nanning 530004, China
| | - Yukun Wang
- Research Center for Optoelectronic Materials and Devices, School of Physical Science and Technology, Guangxi University, Nanning 530004, China
| | - Lixiang Huang
- Research Center for Optoelectronic Materials and Devices, School of Physical Science and Technology, Guangxi University, Nanning 530004, China
| | - Guoxin Li
- Research Center for Optoelectronic Materials and Devices, School of Physical Science and Technology, Guangxi University, Nanning 530004, China
| | - Xin Qiu
- Research Center for Optoelectronic Materials and Devices, School of Physical Science and Technology, Guangxi University, Nanning 530004, China
| | - Xiaoxiao Zhang
- Research Center for Optoelectronic Materials and Devices, School of Physical Science and Technology, Guangxi University, Nanning 530004, China
| | - Wenhong Sun
- Research Center for Optoelectronic Materials and Devices, School of Physical Science and Technology, Guangxi University, Nanning 530004, China
- MOE Key Laboratory of New Processing Technology for Nonferrous Metals and the Guangxi Key of Processing for Non-ferrous Metals and Featured Materials, Guangxi University, Nanning 530004, Guangxi, P. R. China
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Yin H, Xing K, Zhang Y, Dissanayake DMAS, Lu Z, Zhao H, Zeng Z, Yun JH, Qi DC, Yin Z. Periodic nanostructures: preparation, properties and applications. Chem Soc Rev 2021; 50:6423-6482. [PMID: 34100047 DOI: 10.1039/d0cs01146k] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Periodic nanostructures, a group of nanomaterials consisting of single or multiple nano units/components periodically arranged into ordered patterns (e.g., vertical and lateral superlattices), have attracted tremendous attention in recent years due to their extraordinary physical and chemical properties that offer a huge potential for a multitude of applications in energy conversion, electronic and optoelectronic applications. Recent advances in the preparation strategies of periodic nanostructures, including self-assembly, epitaxy, and exfoliation, have paved the way to rationally modulate their ferroelectricity, superconductivity, band gap and many other physical and chemical properties. For example, the recent discovery of superconductivity observed in "magic-angle" graphene superlattices has sparked intensive studies in new ways, creating superlattices in twisted 2D materials. Recent development in the various state-of-the-art preparations of periodic nanostructures has created many new ideas and findings, warranting a timely review. In this review, we discuss the current advances of periodic nanostructures, including their preparation strategies, property modulations and various applications.
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Affiliation(s)
- Hang Yin
- Research School of Chemistry, Australian National University, ACT 2601, Australia.
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Helil Z, Abdiryim T, Jamal R, Kadir A, Che Y, Zou D, Niyaz M. Electrochemical synthesis of hydroxyl group-functionalized PProDOT/ZnO for an ultraviolet photodetector. RSC Adv 2021; 11:15825-15834. [PMID: 35481183 PMCID: PMC9029230 DOI: 10.1039/d1ra01962g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 04/20/2021] [Indexed: 11/21/2022] Open
Abstract
Ultraviolet (UV) detectors based on zinc oxide (ZnO) nanorods (NRs) are ideal materials for UV radiation detection. However, owing to the surface effect of ZnO NRs, their speed of photoresponse and photosensitivity need to be improved. In this study, a UV photodetector was fabricated via electrochemical coating of poly(3,4-propylenedioxythiophene) grafted with functional groups (-OH) on a hydrothermally grown ZnO NRs. For comparison, poly(3,4-propylenedioxythiophene)/ZnO composites were synthesized using the same method. The structure of the composite film was characterized by Fourier transform infrared spectroscopy (FT-IR), UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The effect of the polymer structure on the UV sensing ability of ZnO NRs was evaluated by fabricating a UV detector with a composite material. The structural results indicated that the PProDOT-type conductive polymer and ZnO composites were successfully synthesized. The UV photodetection results showed that the presence of functional groups (-OH) in polymer chains could enhance the responsivity of the material. The response time of the ZnO/PProDOT-OH composite was 15 s shorter than that of the ZnO/PProDOT composite. A rise in photocurrent induced an increase from 2.5 A W-1 to 34.75 A W-1 in the UV photoresponsivity of the ZnO/PProDOT-OH composite, compared with that of the pure ZnO NRs. The external quantum efficiency and detectivity significantly improved, the increases of which were attributed to the coupling of the polymer and ZnO NRs.
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Affiliation(s)
- Zulpikar Helil
- Key Laboratory of Energy Materials Chemistry, Ministry of Education, Key Laboratory of Advanced Functional Materials, Autonomous Region, Institute of Applied Chemistry, College of Chemistry, Xinjiang University Urumqi 830046 P. R. China
| | - Tursun Abdiryim
- Key Laboratory of Energy Materials Chemistry, Ministry of Education, Key Laboratory of Advanced Functional Materials, Autonomous Region, Institute of Applied Chemistry, College of Chemistry, Xinjiang University Urumqi 830046 P. R. China
| | - Ruxangul Jamal
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education, Xinjiang Uygur Autonomous Region, Xinjiang University Urumqi 830046 P. R. China
| | - Aygul Kadir
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education, Xinjiang Uygur Autonomous Region, Xinjiang University Urumqi 830046 P. R. China
| | - Yuzhu Che
- Key Laboratory of Energy Materials Chemistry, Ministry of Education, Key Laboratory of Advanced Functional Materials, Autonomous Region, Institute of Applied Chemistry, College of Chemistry, Xinjiang University Urumqi 830046 P. R. China
| | - Dongna Zou
- Key Laboratory of Energy Materials Chemistry, Ministry of Education, Key Laboratory of Advanced Functional Materials, Autonomous Region, Institute of Applied Chemistry, College of Chemistry, Xinjiang University Urumqi 830046 P. R. China
| | - Mariyam Niyaz
- Key Laboratory of Energy Materials Chemistry, Ministry of Education, Key Laboratory of Advanced Functional Materials, Autonomous Region, Institute of Applied Chemistry, College of Chemistry, Xinjiang University Urumqi 830046 P. R. China
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Spies M, Sadre Momtaz Z, Lähnemann J, Anh Luong M, Fernandez B, Fournier T, Monroy E, I den Hertog M. Correlated and in-situ electrical transmission electron microscopy studies and related membrane-chip fabrication. NANOTECHNOLOGY 2020; 31:472001. [PMID: 32503014 DOI: 10.1088/1361-6528/ab99f0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Understanding the interplay between the structure, composition and opto-electronic properties of semiconductor nano-objects requires combining transmission electron microscopy (TEM) based techniques with electrical and optical measurements on the very same specimen. Recent developments in TEM technologies allow not only the identification and in-situ electrical characterization of a particular object, but also the direct visualization of its modification in-situ by techniques such as Joule heating. Over the past years, we have carried out a number of studies in these fields that are reviewed in this contribution. In particular, we discuss here i) correlated studies where the same unique object is characterized electro-optically and by TEM, ii) in-situ Joule heating studies where a solid-state metal-semiconductor reaction is monitored in the TEM, and iii) in-situ biasing studies to better understand the electrical properties of contacted single nanowires. In addition, we provide detailed fabrication steps for the silicon nitride membrane-chips crucial to these correlated and in-situ measurements.
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Reversible aerobic oxidative dehydrogenation/hydrogenation of N-heterocycles over AlN supported redox cobalt catalysts. MOLECULAR CATALYSIS 2020. [DOI: 10.1016/j.mcat.2020.111192] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Sarkar K, Devi P, Kim KH, Kumar P. III-V nanowire-based ultraviolet to terahertz photodetectors: Device strategies, recent developments, and future possibilities. Trends Analyt Chem 2020. [DOI: 10.1016/j.trac.2020.115989] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Deka Boruah B. Zinc oxide ultraviolet photodetectors: rapid progress from conventional to self-powered photodetectors. NANOSCALE ADVANCES 2019; 1:2059-2085. [PMID: 36131964 PMCID: PMC9416854 DOI: 10.1039/c9na00130a] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 03/28/2019] [Indexed: 05/14/2023]
Abstract
Currently, the development of ultraviolet (UV) photodetectors (PDs) has attracted the attention of the research community because of the vast range of applications of photodetectors in modern society. A variety of wide-band gap nanomaterials have been utilized for UV detection to achieve higher photosensitivity. Specifically, zinc oxide (ZnO) nanomaterials have attracted significant attention primarily due to their additional properties such as piezo-phototronic and pyro-phototronic effects, which allow the fabrication of high-performance and low power consumption-based UV PDs. This article primarily focuses on the recent development of ZnO nanostructure-based UV PDs ranging from nanomaterials to architectural device design. A brief overview of the photoresponse characteristics of UV PDs and potential ZnO nanostructures is presented. Moreover, the recent development in self-powered PDs and implementation of the piezo-phototronic effect, plasmonic effect and pyro-phototronic effect for performance enhancement is highlighted. Finally, the research perspectives and future research direction related to ZnO nanostructures for next-generation UV PDs are summarized.
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Affiliation(s)
- Buddha Deka Boruah
- Institute for Manufacturing, Department of Engineering, University of Cambridge UK CB3 0FS
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10
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Piazza V, Babichev AV, Mancini L, Morassi M, Quach P, Bayle F, Largeau L, Julien FH, Rale P, Collin S, Harmand JC, Gogneau N, Tchernycheva M. Investigation of GaN nanowires containing AlN/GaN multiple quantum discs by EBIC and CL techniques. NANOTECHNOLOGY 2019; 30:214006. [PMID: 30736025 DOI: 10.1088/1361-6528/ab055e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this work, nanoscale electrical and optical properties of n-GaN nanowires (NWs) containing GaN/AlN multiple quantum discs (MQDs) grown by molecular beam epitaxy are investigated by means of single wire I(V) measurements, electron beam induced current microscopy (EBIC) and cathodoluminescence (CL) analysis. A strong impact of non-intentional AlN and GaN shells on the electrical resistance of individual NWs is put in evidence. The EBIC mappings reveal the presence of two regions with internal electric fields oriented in opposite directions: one in the MQDs region and the other in the adjacent bottom GaN segment. These fields are found to co-exist under zero bias, while under an external bias either one or the other dominates the current collection. In this way EBIC maps allow us to locate the current generation within the wire under different bias conditions and to give the first direct evidence of carrier collection from AlN/GaN MQDs. The NWs have been further investigated by photoluminescence and CL analyses at low temperature. CL mappings show that the near band edge emission of GaN from the bottom part of the NW is blue-shifted due to the presence of the radial shell. In addition, it is observed that CL intensity drops in the central part of the NWs. Comparing the CL and EBIC maps, this decrease of the luminescence intensity is attributed to an efficient charge splitting effect due to the electric fields in the MQDs region and in the GaN base.
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Affiliation(s)
- Valerio Piazza
- Centre de Nanosciences et de Nanotechnologies, Université Paris Sud, Avenue de la Vauve, F-91120 Palaiseau, France
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Jiang M, Mao W, Zhou X, Kan C, Shi D. Wavelength-Tunable Waveguide Emissions from Electrically Driven Single ZnO/ZnO:Ga Superlattice Microwires. ACS APPLIED MATERIALS & INTERFACES 2019; 11:11800-11811. [PMID: 30840431 DOI: 10.1021/acsami.9b00851] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Because of the superlattice structures comprising periodic and alternating crystalline layers, one-dimensional photon crystals can be employed to expand immense versatility and practicality of modulating the electronic and photonic propagation behaviors, as well as optical properties. In this work, individual superlattice microwires (MWs) comprising ZnO and Ga-doped ZnO (ZnO/ZnO:Ga) layers were successfully synthesized. Wavelength-tunable multipeak emissions can be realized from electrically driven single superlattice MW-based emission devices, with the dominant wavelengths tuned from ultraviolet to visible spectral regions. To illustrate the multipeak character, single superlattice MWs were selected to construct fluorescent emitters, and the emission wavelength could be tuned from 518 to 562 nm, which is dominated by Ga incorporation. Especially, by introducing Au quasiparticle film decoration, emission characteristics can further be modulated, such as the red shift of the emission wavelengths, and the multipeaks were strongly modified and split into more and narrower subbands. In particular, electrically pumped exciton-polariton emission was realized from heterojunction diodes composed of single ZnO/ZnO:Ga superlattice MWs and p-GaN layers in the blue-ultraviolet spectral regions. With the aid of localized surface plasmons from Au nanoparticles, which deposited on the superlattice MW, significant improvement of emission characteristics, such as enhancement of output efficiencies, blue shift of the dominant emission wavelengths, and narrowing of the spectral linewidth, can be achieved. The multipeak emission characteristics would be originated from the typical optical cavity modes, but not the Fabry-Perot mode optical cavity formed by the bilateral sides of the wire. The resonant modes are likely attributed to the coupled optical microcavities, which formed along the axial direction of the wire; thus, the emitted photons can be propagated and selected longitudinally. Therefore, the novel ZnO/ZnO:Ga superlattice MWs with a quadrilateral cross section can provide a potential platform to construct multicolor emitters and low-threshold exciton-polariton diodes and lasers.
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Lähnemann J, Browne DA, Ajay A, Jeannin M, Vasanelli A, Thomassin JL, Bellet-Amalric E, Monroy E. Near- and mid-infrared intersubband absorption in top-down GaN/AlN nano- and micro-pillars. NANOTECHNOLOGY 2019; 30:054002. [PMID: 30500783 DOI: 10.1088/1361-6528/aaef72] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We present a systematic study of top-down processed GaN/AlN heterostructures for intersubband optoelectronic applications. Samples containing quantum well superlattices that display either near- or mid-infrared intersubband absorption were etched into nano- and micro-pillar arrays in an inductively coupled plasma. We investigate the influence of this process on the structure and strain-state, on the interband emission and on the intersubband absorption. Notably, for pillar spacings significantly smaller (≤1/3) than the intersubband wavelength, the magnitude of the intersubband absorption is not reduced even when 90% of the material is etched away and a similar linewidth is obtained. The same holds for the interband emission. In contrast, for pillar spacings on the order of the intersubband absorption wavelength, the intersubband absorption is masked by refraction effects and photonic crystal modes. The presented results are a first step towards micro- and nano-structured group-III nitride devices relying on intersubband transitions.
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Affiliation(s)
- Jonas Lähnemann
- Université Grenoble-Alpes, CEA, INAC, PHELIQS, 17 av. des Martyrs, F-38000, Grenoble, France. Paul-Drude-Institut für Festkörperelektronik, Leibniz Institut im Forschugnsverbund Berlin e.V., Hausvogteiplatz 5-7, D-10117, Berlin, Germany
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Shi YJ, Zhang RJ, Chen X, Wang L, Chen L, Huang QH, Li DH, Zheng YX, Wang SY, Dai N, Chen LY. Evolution of optical properties and electronic structures: band gaps and critical points in Mg xZn 1-xO (0 ≤ x ≤ 0.2) thin films. Phys Chem Chem Phys 2018; 20:25467-25475. [PMID: 30272075 DOI: 10.1039/c8cp04942d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
MgxZn1-xO (ZMO) thin films with tunable Mg content were deposited by atomic layer deposition (ALD) on silicon substrates at 190 °C. The elemental and structural properties were acquired by X-ray photoelectron spectroscopy, transmission electron microscopy, atomic force microscopy and X-ray diffraction. Spectroscopic ellipsometry measurements were performed to reveal the evolution of the dielectric functions and critical points in the ZMO thin films by point-by-point fit in the photon energy range of 1.2-6.0 eV. The dependence of the dielectric functions on doping content is clearly demonstrated and physically explained. The critical point energies and the types of interband optical transitions were extracted from standard lineshape analysis of the second derivatives of the dielectric functions. The critical point features were discussed in terms of band structure modification and structural homogeneity arisen by introducing the Mg dopant into the films. Controlling these transitions by changing the doping content will be of practical significance in emerging ZMO-based thin-film photonic and optoelectronic devices.
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Affiliation(s)
- Yue-Jie Shi
- Key Laboratory of Micro and Nano Photonic Structures, Ministry of Education, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China.
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Spies M, Polaczyński J, Ajay A, Kalita D, Luong MA, Lähnemann J, Gayral B, den Hertog MI, Monroy E. Effect of the nanowire diameter on the linearity of the response of GaN-based heterostructured nanowire photodetectors. NANOTECHNOLOGY 2018; 29:255204. [PMID: 29558360 DOI: 10.1088/1361-6528/aab838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Nanowire photodetectors are investigated because of their compatibility with flexible electronics, or for the implementation of on-chip optical interconnects. Such devices are characterized by ultrahigh photocurrent gain, but their photoresponse scales sublinearly with the optical power. Here, we present a study of single-nanowire photodetectors displaying a linear response to ultraviolet illumination. Their structure consists of a GaN nanowire incorporating an AlN/GaN/AlN heterostructure, which generates an internal electric field. The activity of the heterostructure is confirmed by the rectifying behavior of the current-voltage characteristics in the dark, as well as by the asymmetry of the photoresponse in magnitude and linearity. Under reverse bias (negative bias on the GaN cap segment), the detectors behave linearly with the impinging optical power when the nanowire diameter is below a certain threshold (≈80 nm), which corresponds to the total depletion of the nanowire stem due to the Fermi level pinning at the sidewalls. In the case of nanowires that are only partially depleted, their nonlinearity is explained by a nonlinear variation of the diameter of their central conducting channel under illumination.
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Affiliation(s)
- Maria Spies
- University Grenoble-Alpes, CNRS, Institut Néel, 25 av. des Martyrs, F-38000 Grenoble, France
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Zarifi MH, Wiltshire B, Mahdi N, Kar P, Shankar K, Daneshmand M. Ultraviolet sensing using a TiO 2 nanotube integrated high resolution planar microwave resonator device. NANOSCALE 2018; 10:4882-4889. [PMID: 29480301 DOI: 10.1039/c7nr06869g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This paper presents a unique integrated UV light sensing concept and introduces a device with a detection limit of 1.96 nW cm-2. The combination of a high quality factor, a microwave planar resonator (Q ∼ 50 000) with a semiconducting nanomaterial enables a revolutionary potential paradigm for photodetection of low light intensities and small form factors. The presenting device employs a high-resolution microwave microstrip resonator as the signal transducer to convert the variant dielectric properties (permittivity and conductivity) of the nanotube membrane into electrical signals such as the resonant frequency, quality factor and resonant amplitude. The microwave resonator has an active feedback loop to improve the initial quality factor of the resonator from 200 to 50 000 and leads to boosting of the sensing resolution by orders of magnitude. Anatase TiO2 nanotubes are assembled on the surface of the microwave resonator. Upon exposure to UV light, electron-hole pair generation, trapping and recombination in the nanotubes are exploited as a unique signature to quantify the UV light intensity. The change of dielectric properties of the nanotube membrane is monitored using the underlying active microwave resonator. The proposed concept enables the detection and monitoring of UV light at high resolution, with very small exposure power and integrated form factors.
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Affiliation(s)
- Mohammad H Zarifi
- School of Engineering, University of British Columbia, Canada V1V 1V7.
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Lähnemann J, Ajay A, Den Hertog MI, Monroy E. Near-Infrared Intersubband Photodetection in GaN/AlN Nanowires. NANO LETTERS 2017; 17:6954-6960. [PMID: 28961016 DOI: 10.1021/acs.nanolett.7b03414] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Intersubband optoelectronic devices rely on transitions between quantum-confined electron levels in semiconductor heterostructures, which enables infrared (IR) photodetection in the 1-30 μm wavelength window with picosecond response times. Incorporating nanowires as active media could enable an independent control over the electrical cross-section of the device and the optical absorption cross-section. Furthermore, the three-dimensional carrier confinement in nanowire heterostructures opens new possibilities to tune the carrier relaxation time. However, the generation of structural defects and the surface sensitivity of GaAs nanowires have so far hindered the fabrication of nanowire intersubband devices. Here, we report the first demonstration of intersubband photodetection in a nanowire, using GaN nanowires containing a GaN/AlN superlattice absorbing at 1.55 μm. The combination of spectral photocurrent measurements with 8-band k·p calculations of the electronic structure supports the interpretation of the result as intersubband photodetection in these extremely short-period superlattices. We observe a linear dependence of the photocurrent with the incident illumination power, which confirms the insensitivity of the intersubband process to surface states and highlights how architectures featuring large surface-to-volume ratios are suitable as intersubband photodetectors. Our analysis of the photocurrent characteristics points out routes for an improvement of the device performance. This first nanowire based intersubband photodetector represents a technological breakthrough that paves the way to a powerful device platform with potential for ultrafast, ultrasensitive photodetectors and highly efficient quantum cascade emitters with improved thermal stability.
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Affiliation(s)
- Jonas Lähnemann
- Université Grenoble-Alpes, CEA, INAC, PHELIQS , 17 av. des Martyrs, 38000 Grenoble, France
| | - Akhil Ajay
- Université Grenoble-Alpes, CEA, INAC, PHELIQS , 17 av. des Martyrs, 38000 Grenoble, France
| | - Martien I Den Hertog
- Université Grenoble-Alpes, CNRS, Institut Néel , 25 av. des Martyrs, 38000 Grenoble, France
| | - Eva Monroy
- Université Grenoble-Alpes, CEA, INAC, PHELIQS , 17 av. des Martyrs, 38000 Grenoble, France
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Müßener J, Hille P, Grieb T, Schörmann J, Teubert J, Monroy E, Rosenauer A, Eickhoff M. Bias-Controlled Optical Transitions in GaN/AlN Nanowire Heterostructures. ACS NANO 2017; 11:8758-8767. [PMID: 28771318 DOI: 10.1021/acsnano.7b02419] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report on the control and modification of optical transitions in 40× GaN/AlN heterostructure superlattices embedded in GaN nanowires by an externally applied bias. The complex band profile of these multi-nanodisc heterostructures gives rise to a manifold of optical transitions, whose emission characteristic is strongly influenced by polarization-induced internal electric fields. We demonstrate that the superposition of an external axial electric field along a single contacted nanowire leads to specific modifications of each photoluminescence emission, which allows to investigate and identify their origin and to control their characteristic properties in terms of transition energy, intensity and decay time. Using this approach, direct transitions within one nanodisc, indirect transitions between adjacent nanodiscs, transitions at the top/bottom edge of the heterostructure, and the GaN near-band-edge emission can be distinguished. While the transition energy of the direct transition can be shifted by external bias over a range of 450 meV and changed in intensity by a factor of 15, the indirect transition exhibits an inverse bias dependence and is only observable and spectrally separated when external bias is applied. In addition, by tuning the band profile close to flat band conditions, the direction and magnitude of the internal electric field can be estimated, which is of high interest for the polar group III-nitrides. The direct control of emission properties over a wide range bears possible application in tunable optoelectronic devices. For more fundamental studies, single-nanowire heterostructures provide a well-defined and isolated system to investigate and control interaction processes in coupled quantum structures.
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Affiliation(s)
- Jan Müßener
- Institut für Festkörperphysik, Universität Bremen , Otto-Hahn-Allee 1, 28359 Bremen, Germany
- I. Physikalisches Institut, Justus-Liebig-Universität Gießen , Heinrich-Buff-Ring 16, 35392 Gießen, Germany
| | - Pascal Hille
- Institut für Festkörperphysik, Universität Bremen , Otto-Hahn-Allee 1, 28359 Bremen, Germany
- I. Physikalisches Institut, Justus-Liebig-Universität Gießen , Heinrich-Buff-Ring 16, 35392 Gießen, Germany
| | - Tim Grieb
- Institut für Festkörperphysik, Universität Bremen , Otto-Hahn-Allee 1, 28359 Bremen, Germany
| | - Jörg Schörmann
- I. Physikalisches Institut, Justus-Liebig-Universität Gießen , Heinrich-Buff-Ring 16, 35392 Gießen, Germany
| | - Jörg Teubert
- I. Physikalisches Institut, Justus-Liebig-Universität Gießen , Heinrich-Buff-Ring 16, 35392 Gießen, Germany
| | - Eva Monroy
- Université Grenoble-Alpes , 38000 Grenoble, France
- CEA-Grenoble, INAC-PHELIQS , 17 Avenue des Martyrs, 38054 Grenoble, France
| | - Andreas Rosenauer
- Institut für Festkörperphysik, Universität Bremen , Otto-Hahn-Allee 1, 28359 Bremen, Germany
| | - Martin Eickhoff
- Institut für Festkörperphysik, Universität Bremen , Otto-Hahn-Allee 1, 28359 Bremen, Germany
- I. Physikalisches Institut, Justus-Liebig-Universität Gießen , Heinrich-Buff-Ring 16, 35392 Gießen, Germany
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18
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Spies M, den Hertog MI, Hille P, Schörmann J, Polaczyński J, Gayral B, Eickhoff M, Monroy E, Lähnemann J. Bias-Controlled Spectral Response in GaN/AlN Single-Nanowire Ultraviolet Photodetectors. NANO LETTERS 2017; 17:4231-4239. [PMID: 28613893 DOI: 10.1021/acs.nanolett.7b01118] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We present a study of GaN single-nanowire ultraviolet photodetectors with an embedded GaN/AlN superlattice. The heterostructure dimensions and doping profile were designed in such a way that the application of positive or negative bias leads to an enhancement of the collection of photogenerated carriers from the GaN/AlN superlattice or from the GaN base, respectively, as confirmed by electron beam-induced current measurements. The devices display enhanced response in the ultraviolet A (≈ 330-360 nm)/B (≈ 280-330 nm) spectral windows under positive/negative bias. The result is explained by correlation of the photocurrent measurements with scanning transmission electron microscopy observations of the same single nanowire and semiclassical simulations of the strain and band structure in one and three dimensions.
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Affiliation(s)
- Maria Spies
- University Grenoble-Alpes , 38000 Grenoble, France
- CNRS-Institut Néel , 25 avenue des Martyrs, 38000 Grenoble, France
| | - Martien I den Hertog
- University Grenoble-Alpes , 38000 Grenoble, France
- CNRS-Institut Néel , 25 avenue des Martyrs, 38000 Grenoble, France
| | - Pascal Hille
- I. Physikalisches Institut, Justus Liebig Universität Gießen , Heinrich-Buff-Ring 16, 35390 Gießen, Germany
- Institut für Festkörperphysik, Universität Bremen , 28359 Bremen, Germany
| | - Jörg Schörmann
- I. Physikalisches Institut, Justus Liebig Universität Gießen , Heinrich-Buff-Ring 16, 35390 Gießen, Germany
| | - Jakub Polaczyński
- University Grenoble-Alpes , 38000 Grenoble, France
- CNRS-Institut Néel , 25 avenue des Martyrs, 38000 Grenoble, France
| | - Bruno Gayral
- University Grenoble-Alpes , 38000 Grenoble, France
- CEA-INAC-PHELIQS , 17 avenue des Martyrs, 38000 Grenoble, France
| | - Martin Eickhoff
- I. Physikalisches Institut, Justus Liebig Universität Gießen , Heinrich-Buff-Ring 16, 35390 Gießen, Germany
- Institut für Festkörperphysik, Universität Bremen , 28359 Bremen, Germany
| | - Eva Monroy
- University Grenoble-Alpes , 38000 Grenoble, France
- CEA-INAC-PHELIQS , 17 avenue des Martyrs, 38000 Grenoble, France
| | - Jonas Lähnemann
- University Grenoble-Alpes , 38000 Grenoble, France
- CEA-INAC-PHELIQS , 17 avenue des Martyrs, 38000 Grenoble, France
- Paul-Drude-Institut für Festkörperelektronik , Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, 10117 Berlin, Germany
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Karimi M, Jain V, Heurlin M, Nowzari A, Hussain L, Lindgren D, Stehr JE, Buyanova IA, Gustafsson A, Samuelson L, Borgström MT, Pettersson H. Room-temperature InP/InAsP Quantum Discs-in-Nanowire Infrared Photodetectors. NANO LETTERS 2017; 17:3356-3362. [PMID: 28535059 DOI: 10.1021/acs.nanolett.6b05114] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The possibility to engineer nanowire heterostructures with large bandgap variations is particularly interesting for technologically important broadband photodetector applications. Here we report on a combined study of design, fabrication, and optoelectronic properties of infrared photodetectors comprising four million n+-i-n+ InP nanowires periodically ordered in arrays. The nanowires were grown by metal-organic vapor phase epitaxy on InP substrates, with either a single or 20 InAsP quantum discs embedded in the i-segment. By Zn compensation of the residual n-dopants in the i-segment, the room-temperature dark current is strongly suppressed to a level of pA/NW at 1 V bias. The low dark current is manifested in the spectrally resolved photocurrent measurements, which reveal strong photocurrent contributions from the InAsP quantum discs at room temperature with a threshold wavelength of about 2.0 μm and a bias-tunable responsivity reaching 7 A/W@1.38 μm at 2 V bias. Two different processing schemes were implemented to study the effects of radial self-gating in the nanowires induced by the nanowire/SiOx/ITO wrap-gate geometry. Summarized, our results show that properly designed axial InP/InAsP nanowire heterostructures are promising candidates for broadband photodetectors.
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Affiliation(s)
- Mohammad Karimi
- Solid State Physics and NanoLund, Lund University , Box 118, SE-221 00 Lund, Sweden
- Department of Mathematics, Physics and Electrical Engineering, Halmstad University , Box 823, SE-301 18 Halmstad, Sweden
| | - Vishal Jain
- Solid State Physics and NanoLund, Lund University , Box 118, SE-221 00 Lund, Sweden
- Department of Mathematics, Physics and Electrical Engineering, Halmstad University , Box 823, SE-301 18 Halmstad, Sweden
| | - Magnus Heurlin
- Solid State Physics and NanoLund, Lund University , Box 118, SE-221 00 Lund, Sweden
| | - Ali Nowzari
- Solid State Physics and NanoLund, Lund University , Box 118, SE-221 00 Lund, Sweden
| | - Laiq Hussain
- Solid State Physics and NanoLund, Lund University , Box 118, SE-221 00 Lund, Sweden
- Department of Mathematics, Physics and Electrical Engineering, Halmstad University , Box 823, SE-301 18 Halmstad, Sweden
| | - David Lindgren
- Solid State Physics and NanoLund, Lund University , Box 118, SE-221 00 Lund, Sweden
| | - Jan Eric Stehr
- Department of Physics, Chemistry and Biology, Linköping University , SE-581 83 Linköping, Sweden
| | - Irina A Buyanova
- Department of Physics, Chemistry and Biology, Linköping University , SE-581 83 Linköping, Sweden
| | - Anders Gustafsson
- Solid State Physics and NanoLund, Lund University , Box 118, SE-221 00 Lund, Sweden
| | - Lars Samuelson
- Solid State Physics and NanoLund, Lund University , Box 118, SE-221 00 Lund, Sweden
| | - Magnus T Borgström
- Solid State Physics and NanoLund, Lund University , Box 118, SE-221 00 Lund, Sweden
| | - Håkan Pettersson
- Solid State Physics and NanoLund, Lund University , Box 118, SE-221 00 Lund, Sweden
- Department of Mathematics, Physics and Electrical Engineering, Halmstad University , Box 823, SE-301 18 Halmstad, Sweden
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20
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Zhang X, Liu B, Liu Q, Yang W, Xiong C, Li J, Jiang X. Ultrasensitive and Highly Selective Photodetections of UV-A Rays Based on Individual Bicrystalline GaN Nanowire. ACS APPLIED MATERIALS & INTERFACES 2017; 9:2669-2677. [PMID: 28029770 DOI: 10.1021/acsami.6b14907] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The detection of UV-A rays (wavelength of 320-400 nm) using functional semiconductor nanostructures is of great importance in either fundamental research or technological applications. In this work, we report the catalytic synthesis of peculiar bicrystalline GaN nanowires and their utilization for building high-performance optoelectronic nanodevices. The as-prepared UV-A photodetector based on individual bicrystalline GaN nanowire demonstrates a fast photoresponse time (144 ms), a high wavelength selectivity (UV-A light response only), an ultrahigh photoresponsivity of 1.74 × 107 A/W and EQE of 6.08 × 109%, a sensitivity of 2 × 104%, and a very large on/off ratio of more than two orders, as well as robust photocurrent stability (photocurrent fluctuation of less than 7% among 4000 s), showing predominant advantages in comparison with other peer semiconductor photodetectors. The outstanding optoelectronic performance of the bicrystalline GaN nanowire UV-A photodetector is further analyzed based on a detailed high-resolution transmission electron microscope (HRTEM) study, and the two separated crystal domains within the GaN nanowires are believed to provide separated and rapid carrier transfer channels. This work paves a solid way toward the integration of high-performance optoelectronic nanodevices based on bicrystalline or horizontally aligned one-dimensional semiconductor nanostructures.
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Affiliation(s)
- Xinglai Zhang
- Shenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , No. 72 Wenhua Road, Shenyang 110016 China
| | - Baodan Liu
- Shenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , No. 72 Wenhua Road, Shenyang 110016 China
| | - Qingyun Liu
- Shenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , No. 72 Wenhua Road, Shenyang 110016 China
| | - Wenjin Yang
- Shenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , No. 72 Wenhua Road, Shenyang 110016 China
| | - Changmin Xiong
- Department of Physics, Beijing Normal University , 100875, Beijing, P. R. China
| | - Jing Li
- Shenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , No. 72 Wenhua Road, Shenyang 110016 China
| | - Xin Jiang
- Shenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , No. 72 Wenhua Road, Shenyang 110016 China
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