1
|
Nadtochenko V, Cherepanov D, Kochev S, Motyakin M, Kostrov A, Golub A, Antonova O, Kabachii Y, Rtimi S. Structural and optical properties of Mn2+-doped ZnCdS/ZnS core/shell quantum dots: New insights in Mn2+ localization for higher luminescence sensing. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.113946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
2
|
Gogoi H, Pathak SS, Dasgupta S, Panchakarla LS, Nath S, Datta A. Exciton Dynamics in Colloidal CdS Quantum Dots with Intense and Stokes Shifted Photoluminescence in a Single Decay Channel. J Phys Chem Lett 2022; 13:6770-6776. [PMID: 35853205 DOI: 10.1021/acs.jpclett.2c01623] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
CdS quantum dots (QDs), synthesized by a sol-gel method, exhibit significantly Stokes shifted bright photoluminescence (PL), predominantly from the trap states. Surprisingly, the PL decay at the emission maximum is single-exponential. This is an unusual observation for as-prepared QDs and indicates a narrow distribution in the nature of trap states. A closer look reveals an additional fast component for the decays at shorter emission wavelengths, presumably due to the band edge emission, which remains elusive in the steady-state spectra. Indeed, a significantly narrower and blue-shifted emission band is observed in the decay-associated spectra. The contribution of this component to the steady-state PL intensity is shown to be overwhelmed by that of the significantly stronger trap emission. Exciton dynamics in the quantum dots is elucidated using transient absorption spectra, in which the stimulated emission is observed even at low pump power.
Collapse
Affiliation(s)
- Hemen Gogoi
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Sushil Swaroop Pathak
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Souradip Dasgupta
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | | | - Sukhendu Nath
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400 094, India
| | - Anindya Datta
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| |
Collapse
|
3
|
Liu H, Wang Y, Yang X, Zhao X, Wang K, Wu M, Zuo X, Yang W, Sui Y, Zou B. Pressure-stimulus-responsive behaviors of core-shell InP/ZnSe nanocrystals: remarkable piezochromic luminescence and structural assembly. NANOSCALE 2022; 14:7530-7537. [PMID: 35481922 DOI: 10.1039/d2nr00281g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Piezochromic luminescence materials with optical properties can be adjusted (the colors most sensitive to the human eye range from red to green) to provide powerful means for information acquisition in various applications. Inorganic quantum dots, typically based on heavy metals such as cadmium and lead, have congenital advantages as luminescence materials, including strong inoxidizability and excellent photoelectric properties. However, small band-gap shifts under pressure have hindered the development of inorganic-based piezochromic materials. Herein, we combined in situ high-pressure photoluminescence (PL) and absorption measurements with synchrotron X-ray scattering spectra to elucidate the remarkable modulation of optical properties and morphologies by pressure, particularly that of the piezochromic luminescence, in all-inorganic core-shell InP/ZnSe nanocrystals (NCs). We observed a stepwise PL color change from red to green, and an ultrabroad bandgap tunability of 0.46 eV was observed from 1.99 to 2.45 eV in the pressure range of 14.2 GPa for InP/ZnSe NCs. Moreover, two-dimensional (2D) InP/ZnSe nanosheets were synthesized by the stress-driven attachment of nanoparticles. These results demonstrate the ability of the pressure-stimulus response to trigger remarkable piezochromic luminescence and 2D nanosheet assembly in InP/ZnSe NCs, which paves the way for new applications of all-inorganic InP-based semiconductor NCs.
Collapse
Affiliation(s)
- Hao Liu
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China.
- School of Physics and Electronic Engineering, Xinxiang University, Xinxiang 453003, China
| | - Yixuan Wang
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China.
| | - Xinyi Yang
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China.
| | - Xiaohui Zhao
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China.
| | - Kai Wang
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China.
| | - Min Wu
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China.
| | - Xiaobing Zuo
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Wenge Yang
- Center for High-Pressure Science and Technology Advanced Research, Beijing 100094, China
| | - Yongming Sui
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China.
| | - Bo Zou
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China.
| |
Collapse
|
4
|
Ali F, Das S, Banerjee S, Maddala BG, Rana G, Datta A. Intense photoluminescence from Cu-doped CdSe nanotetrapods triggered by ultrafast hole capture. NANOSCALE 2021; 13:14228-14235. [PMID: 34477705 DOI: 10.1039/d1nr03833h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Brightly photoluminescent Cu-doped CdSe nanotetrapods (NTPs) have been prepared by a modified hot injection method. Their photoluminescence (PL) has a quantum yield of 38% and decays slowly over a few microseconds, while the PL in undoped NTPs has a rather small quantum yield of 1.7% and decays predominantly in tens of picoseconds, with a minor component in the nanosecond time regime. PL spectra of doped NTPs are significantly Stokes shifted compared to the band edge (BE). Efficient PL quenching by a hole scavenger confirms the oxidation state of +I for the dopant ion and establishes hole capture by this ion to be the primary event that leads to the Stokes shifted PL. A fast decay of the photoinduced absorption band, along with a similar decay in PL, observed in a femtosecond optical gating experiment, yields a time constant of about a picosecond for the hole capture from the valence band (VB) by Cu+. The remarkably long PL lifetime in the doped NTPs is ascribed to the decrease in the overlap between the wavefunctions of the photogenerated electrons and the captured hole. Hot carrier relaxation processes, triggered by excitation at energies greater than the band gap, leave their signature in a rise time of few hundreds of femtoseconds, in the ground state bleach recovery kinetics. Hence, a complete picture of exciton dynamics in the doped NTPs has been obtained using ultrafast spectroscopic techniques working in tandem.
Collapse
Affiliation(s)
- Fariyad Ali
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India.
| | | | | | | | | | | |
Collapse
|
5
|
Temperature-dependent anomalous Mn2+ emission and excited state dynamics in Mn2+-doped MAPbCl3-xBrx nanocrystals. J CHEM SCI 2021. [DOI: 10.1007/s12039-021-01919-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
6
|
Enhancement of photocatalytic by Mn3O4 spinel ferrite decorated graphene oxide nanocomposites. SN APPLIED SCIENCES 2021. [DOI: 10.1007/s42452-021-04644-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Abstract
The hydrothermal process was used to prepare Mn3O4/x%GO nanocomposites (NC’s) having different ratios of the Mn3O4 nanoparticles (NP’s) on the surface of graphene oxide (GO) sheet. SEM image showed that the Mn3O4 NP’s were distributed over the surface of GO sheet. HRTEM images exhibited the lattice fringe arising from the (101) plane of the Mn3O4 NP’s having the interplanar d-spacing of 0.49 nm decorating on the surface of GO. The electronic absorption spectra of Mn3O4/x%GO NC’s also show broad bands from 250 to 550 nm. These bands arise from the d–d crystal field transitions of the tetrahedral Mn3+ species and indicate a distortion in the crystal structure. Photo-catalytic activity of spinel ferrite Mn3O4 NP’s by themselves was low but photo-catalytic activity is enhanced when the NP’s are decorating the GO sheet. Moreover, the Mn3O4/10%GO NC’s showed the best photo-catalytic activity. This result comes from the formation of Mn–O–C bond that confirm by FT-IR. This bond would facilitate the transfer of the photoelectrons from the surfaces of the NP’s to the GO sheets. PL emission which is in the violet–red luminescent region shows the creation of defects in the fabricated Mn3O4 NP’s nanostructures. These defects create the defect states to which electrons in the VB can be excited to when the CB. The best degradation efficiency was achieved by the Mn3O4 NP’s when they were used to decorate the GO sheets in the Mn3O4/10%GO NC’s solution.
Highlights
Lattice fringe of Mn3O4 with an interplanar d-spacing of 0.49 nm for (101) plane.
Photocatalytic activity of spinel ferrite Mn3O4 nanoparticles by itself is low.
Number of photoelectrons created depends on number of Mn3O4 on a given area of GO
The bonding of the Mn3O4 to the GO sheet would be though a Mn–O–C junction.
The degradation processes were accelerated by Mn3O4/10%GO nanocomposites
Graphic abstract
Collapse
|
7
|
Devaiah Chonamada T, Sharma B, Nagesh J, Shibu A, Das S, Bramhaiah K, Rajendar N, John NS, Santra PK. Origin of Luminescence‐Based Detection of Metal Ions by Mn–Doped ZnS Quantum Dots. ChemistrySelect 2019. [DOI: 10.1002/slct.201903769] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Trupthi Devaiah Chonamada
- Centre for Nano and Soft Matter Sciences, Jalahalli Bengaluru 560013 India
- Manipal Academy of Higher Education Manipal 576104 India
| | - Bhagwati Sharma
- Centre for Nano and Soft Matter Sciences, Jalahalli Bengaluru 560013 India
- Currently at Materials Research CentreMalaviya National Institute of Technology Jaipur- 302017 India
| | - Jayashree Nagesh
- Solid State and Structural Chemistry UnitIndian Institute of Science Bengaluru 560012 India
| | - Abhishek Shibu
- Centre for Nano and Soft Matter Sciences, Jalahalli Bengaluru 560013 India
| | - Shyamashis Das
- Solid State and Structural Chemistry UnitIndian Institute of Science Bengaluru 560012 India
| | - Kommula Bramhaiah
- Centre for Nano and Soft Matter Sciences, Jalahalli Bengaluru 560013 India
| | - Nasani Rajendar
- Department of ChemistryIndian Institute of Science Education and Research Bhopal, Bhauri Bhopal 462066 India
| | - Neena S. John
- Centre for Nano and Soft Matter Sciences, Jalahalli Bengaluru 560013 India
| | - Pralay K. Santra
- Centre for Nano and Soft Matter Sciences, Jalahalli Bengaluru 560013 India
| |
Collapse
|
8
|
Parobek D, Qiao T, Son DH. Energetic hot electrons from exciton-to-hot electron upconversion in Mn-doped semiconductor nanocrystals. J Chem Phys 2019; 151:120901. [PMID: 31575181 DOI: 10.1063/1.5119398] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Generation of hot electrons and their utilization in photoinduced chemical processes have been the subjects of intense research in recent years mostly exploring hot electrons in plasmonic metal nanostructures created via decay of optically excited plasmon. Here, we present recent progress made in generation and utilization of a different type of hot electrons produced via biphotonic exciton-to-hot electron "upconversion" in Mn-doped semiconductor nanocrystals. Compared to the plasmonic hot electrons, those produced via biphotonic upconversion in Mn-doped semiconductor nanocrystals possess much higher energy, enabling more efficient long-range electron transfer across the high energy barrier. They can even be ejected above the vacuum level creating photoelectrons, which can possibly produce solvated electrons. Despite the biphotonic nature of the upconversion process, hot electrons can be generated with weak cw excitation equivalent to the concentrated solar radiation without requiring intense or high-energy photons. This perspective reviews recent work elucidating the mechanism of generating energetic hot electrons in Mn-doped semiconductor nanocrystals, detection of these hot electrons as photocurrent or photoelectron emission, and their utilization in chemical processes such as photocatalysis. New opportunities that the energetic hot electrons can open by creating solvated electrons, which can be viewed as the longer-lived and mobile version of hot electrons more useful for chemical processes, and the challenges in practical utilization of energetic hot electrons are also discussed.
Collapse
Affiliation(s)
- David Parobek
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - Tian Qiao
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - Dong Hee Son
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| |
Collapse
|
9
|
Sun C, Gao Z, Deng Y, Liu H, Wang L, Su S, Li P, Li H, Zhang Z, Bi W. Orange to Red, Emission-Tunable Mn-Doped Two-Dimensional Perovskites with High Luminescence and Stability. ACS APPLIED MATERIALS & INTERFACES 2019; 11:34109-34116. [PMID: 31441301 DOI: 10.1021/acsami.9b11665] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Lead halide perovskites are emerging as promising candidates for high-efficiency light-emitting diode (LED) applications because of their tunable band gaps and high quantum yield (QY). However, it remains a challenge to obtain stable red emitting materials with high QY. Herein, we report a facile and convenient hot-injection strategy to synthesize Mn-doped two-dimensional (2D) perovskite nanosheets. The emission peak can be tuned from 597 to 658 nm by manipulating the crystal field strength. In particular, a QY as high as 97% for 2D perovskite is achieved. The as-prepared perovskite also possesses excellent stability, whose emission property can be maintained for almost one year. A monochrome LED is further fabricated by employing the as-prepared perovskite as phosphor, which also shows high long-term stability. We believe that these highly efficient and stable perovskites will open up new opportunities in LED applications.
Collapse
Affiliation(s)
| | | | - Yuchen Deng
- Hebei Provincial Key Lab of Green Chemical Technology and High Efficient Energy Saving, School of Chemical Engineering and Technology , Hebei University of Technology , Tianjin 300130 , P. R. China
| | | | | | | | - Peng Li
- Hebei Provincial Key Lab of Green Chemical Technology and High Efficient Energy Saving, School of Chemical Engineering and Technology , Hebei University of Technology , Tianjin 300130 , P. R. China
| | - Huanrong Li
- Hebei Provincial Key Lab of Green Chemical Technology and High Efficient Energy Saving, School of Chemical Engineering and Technology , Hebei University of Technology , Tianjin 300130 , P. R. China
| | | | | |
Collapse
|
10
|
Haris MPU, Bakthavatsalam R, Shaikh S, Kore BP, Moghe D, Gonnade RG, Sarma DD, Kabra D, Kundu J. Synthetic Control on Structure/Dimensionality and Photophysical Properties of Low Dimensional Organic Lead Bromide Perovskite. Inorg Chem 2018; 57:13443-13452. [DOI: 10.1021/acs.inorgchem.8b02042] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Muhammed P. U. Haris
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune, Dr. Homi Bhabha Road, Pashan Pune, Maharashtra-411008, India
| | - Rangarajan Bakthavatsalam
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune, Dr. Homi Bhabha Road, Pashan Pune, Maharashtra-411008, India
| | - Samir Shaikh
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune, Dr. Homi Bhabha Road, Pashan Pune, Maharashtra-411008, India
| | - Bhushan P. Kore
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, CV Raman Rd, Bengaluru, Karnataka-560012, India
| | - Dhanashree Moghe
- Department of Physics, Indian Institute of Technology Bombay, Main Gate Road, Powai, Mumbai, Maharashtra-400076, India
| | - Rajesh G. Gonnade
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune, Dr. Homi Bhabha Road, Pashan Pune, Maharashtra-411008, India
| | - D. D. Sarma
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, CV Raman Rd, Bengaluru, Karnataka-560012, India
| | - Dinesh Kabra
- Department of Physics, Indian Institute of Technology Bombay, Main Gate Road, Powai, Mumbai, Maharashtra-400076, India
| | - Janardan Kundu
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune, Dr. Homi Bhabha Road, Pashan Pune, Maharashtra-411008, India
| |
Collapse
|
11
|
Zhu J, Mei S, Yang W, Zhang G, Chen Q, Zhang W, Guo R. Tunable emission of Cu (Mn)-doped ZnInS quantum dots via dopant interaction. J Colloid Interface Sci 2017; 506:27-35. [DOI: 10.1016/j.jcis.2017.06.043] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 06/12/2017] [Accepted: 06/14/2017] [Indexed: 10/19/2022]
|
12
|
Pradhan N, Das Adhikari S, Nag A, Sarma DD. Luminescence, Plasmonic, and Magnetic Properties of Doped Semiconductor Nanocrystals. Angew Chem Int Ed Engl 2017; 56:7038-7054. [DOI: 10.1002/anie.201611526] [Citation(s) in RCA: 168] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 01/18/2017] [Indexed: 12/25/2022]
Affiliation(s)
- Narayan Pradhan
- Department of Materials Science; Indian Association for the Cultivation of Science; Kolkata 700032 India
| | - Samrat Das Adhikari
- Department of Materials Science; Indian Association for the Cultivation of Science; Kolkata 700032 India
| | - Angshuman Nag
- Department of Chemistry and Centre for Energy Science; Indian Institute of Science Education and Research, IISER; Pune 411008 India
| | - D. D. Sarma
- Solid State and Structural Chemistry Unit; Indian Institute of Science; Bengaluru 560012 India
| |
Collapse
|
13
|
Pradhan N, Das Adhikari S, Nag A, Sarma DD. Dotierte Halbleiter-Nanokristalle: Lumineszenz, plasmonische und magnetische Eigenschaften. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201611526] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Narayan Pradhan
- Department of Materials Science; Indian Association for the Cultivation of Science; Kolkata 700032 Indien
| | - Samrat Das Adhikari
- Department of Materials Science; Indian Association for the Cultivation of Science; Kolkata 700032 Indien
| | - Angshuman Nag
- Department of Chemistry and Centre for Energy Science; Indian Institute of Science Education and Research, IISER; Pune 411008 Indien
| | - D. D. Sarma
- Solid State and Structural Chemistry Unit; Indian Institute of Science; Bengaluru 560012 Indien
| |
Collapse
|
14
|
Pandey A, Sarma DD. Recent Advances in Manganese Doped II-VI Semiconductor Quantum Dots. Z Anorg Allg Chem 2016. [DOI: 10.1002/zaac.201600368] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Anshu Pandey
- Solid State and Structural Chemistry Unit; Indian Institute of Science; 560012 Bangalore India
| | - Dipankar Das Sarma
- Solid State and Structural Chemistry Unit; Indian Institute of Science; 560012 Bangalore India
| |
Collapse
|
15
|
Saha A, Shetty A, Pavan AR, Chattopadhyay S, Shibata T, Viswanatha R. Uniform Doping in Quantum-Dots-Based Dilute Magnetic Semiconductor. J Phys Chem Lett 2016; 7:2420-2428. [PMID: 27295453 DOI: 10.1021/acs.jpclett.6b01099] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Effective manipulation of magnetic spin within a semiconductor leading to a search for ferromagnets with semiconducting properties has evolved into an important field of dilute magnetic semiconductors (DMS). Although a lot of research is focused on understanding the still controversial origin of magnetism, efforts are also underway to develop new materials with higher magnetic temperatures for spintronics applications. However, so far, efforts toward quantum-dots(QDs)-based DMS materials are plagued with problems of phase separation, leading to nonuniform distribution of dopant ions. In this work, we have developed a strategy to synthesize highly crystalline, single-domain DMS system starting from a small magnetic core and allowing it to diffuse uniformly inside a thick CdS semiconductor matrix and achieve DMS QDs. X-ray absorption fine structure (XAFS) spectroscopy and energy-dispersive X-ray spectroscopy-scanning transmission electron microscopy (STEM-EDX) indicates the homogeneous distribution of magnetic impurities inside the semiconductor QDs leading to superior magnetic property. Further, the versatility of this technique was demonstrated by obtaining ultra large particles (∼60 nm) with uniform doping concentration as well as demonstrating the high quality magnetic response.
Collapse
Affiliation(s)
| | | | | | - Soma Chattopadhyay
- Sector 10 ID, CSRRI-IIT, Advanced Photon Source, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
- Advanced Materials Group, Physics Department, Illinois Institute of Technology , Chicago, Illinois 60616, United States
| | - Tomohiro Shibata
- MRCAT, Argonne National Laboratory , Argonne, Illinois 60439, United States
- Advanced Materials Group, Physics Department, Illinois Institute of Technology , Chicago, Illinois 60616, United States
| | | |
Collapse
|
16
|
Pradhan N. Red-Tuned Mn d-d Emission in Doped Semiconductor Nanocrystals. Chemphyschem 2016; 17:1087-94. [PMID: 26632423 DOI: 10.1002/cphc.201500953] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Indexed: 12/30/2022]
Abstract
Light-emitting Mn-doped semiconductor nanocrystals have been extensively studied for the last three decades for their intense and stable Mn d-d emission. In principle, this emission should be fixed at 585 nm (yellow), but recent studies have shown that the emission can be widely tuned even to 650 nm (red). This is a spectacular achievement as this would make Mn-doped nanocrystals efficient and tunable light emitters. Keeping these developments in view, the chemistry of the synthesis of these materials, their photophysical processes and the expected origins of their red emission are summarized in this Minireview. All the related important studies from 1992 onwards are chronologically discussed, and one particular case is elaborated on in detail. As these materials are potentially important for biology, and photovoltaic, sensing and light-emitting devices, this Minireview is expected to help researchers investigating the chemistry, physics and applications of these materials.
Collapse
Affiliation(s)
- Narayan Pradhan
- Department of Materials Science, Indian Association for the Cultivation of Science, Kolkata, 700032, India.
| |
Collapse
|
17
|
Jagadeeswararao M, Pal S, Nag A, Sarma DD. Electrical and Plasmonic Properties of Ligand-Free Sn4+-Doped In2O3(ITO) Nanocrystals. Chemphyschem 2016; 17:710-6. [DOI: 10.1002/cphc.201500973] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Metikoti Jagadeeswararao
- Department of Chemistry; Indian Institute of Science Education and Research (IISER); Pune 411008 India
| | - Somnath Pal
- Solid State and Structural Chemistry Unit; Indian Institute of Science; Bangalore 560012 India
| | - Angshuman Nag
- Department of Chemistry; Indian Institute of Science Education and Research (IISER); Pune 411008 India
| | - D. D. Sarma
- Solid State and Structural Chemistry Unit; Indian Institute of Science; Bangalore 560012 India
- Department of Physics and Astronomy; Uppsala University; Box 516 75120 Uppsala Sweden
- Council of Scientific and Industrial Research-Network of Institutes for Solar Energy (CSIR-NISE); New Delhi 110001 India
| |
Collapse
|
18
|
Zhai Y, Shim M. Benefitting from Dopant Loss and Ostwald Ripening in Mn Doping of II-VI Semiconductor Nanocrystals. NANOSCALE RESEARCH LETTERS 2015; 10:423. [PMID: 26510444 PMCID: PMC4624686 DOI: 10.1186/s11671-015-1123-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 10/15/2015] [Indexed: 06/05/2023]
Abstract
Annealing or growth at high temperatures for an extended period of time is considered detrimental for most synthetic strategies for high-quality Mn-doped II-VI semiconductor nanocrystals. It can lead to the broadening of size distribution and, more importantly, to the loss of dopants. Here, we examine how ripening can be beneficial to doping in a simple "heat-up" approach, where high dopant concentrations can be achieved. We discuss the interplay of the loss of dopants, Ostwald ripening, and the clustering of Mn near the surface during nanocrystal growth. Smaller nanocrystals in a reaction batch, on average, exhibit higher undesirable band-edge photoluminescence (PL) and lower desirable dopant PL. The optimization of dopant loss and the removal of such smaller undesirable nanocrystals through Ostwald ripening along with surface exchange/passivation to remove Mn clustering lead to high Mn PL quantum yields (45 to 55 %) for ZnSxSe1-x, ZnS, CdS, and CdSxSe1-x host nanocrystals. These results provide an improved understanding of the doping process in a simple and potentially scalable synthetic strategy for achieving "pure" and bright dopant emission.
Collapse
Affiliation(s)
- You Zhai
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Moonsub Shim
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
| |
Collapse
|
19
|
Peng L, Huang K, Zhang Z, Zhang Y, Shi Z, Xie R, Yang W. Bandgap- and Radial-Position-Dependent Mn-Doped Zn-Cu-In-S/ZnS Core/Shell Nanocrystals. Chemphyschem 2015; 17:752-8. [DOI: 10.1002/cphc.201500787] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Indexed: 12/26/2022]
Affiliation(s)
- Lucheng Peng
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry; College of Chemistry; Jilin University; Changchun 130012 China
| | - Keke Huang
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry; College of Chemistry; Jilin University; Changchun 130012 China
| | - Zhuolei Zhang
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry; College of Chemistry; Jilin University; Changchun 130012 China
| | - Ying Zhang
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry; College of Chemistry; Jilin University; Changchun 130012 China
| | - Zhan Shi
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry; College of Chemistry; Jilin University; Changchun 130012 China
| | - Renguo Xie
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry; College of Chemistry; Jilin University; Changchun 130012 China
| | - Wensheng Yang
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry; College of Chemistry; Jilin University; Changchun 130012 China
| |
Collapse
|
20
|
Wang Y, Liang X, Liu E, Hu X, Fan J. Incorporation of lanthanide (Eu(3+)) ions in ZnS semiconductor quantum dots with a trapped-dopant model and their photoluminescence spectroscopy study. NANOTECHNOLOGY 2015; 26:375601. [PMID: 26303203 DOI: 10.1088/0957-4484/26/37/375601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Doping quantum dots (QDs) with lanthanide (Ln) ions is promising to modify the optical properties of QDs, but incorporating Ln(3+) ions into QD hosts remains a challenge. In this work, we adopt the trapped-dopant model for fabricating Eu-doped ZnS QDs via direct wet chemical synthesis. Sharp Eu dopant photoluminescence (PL) was observed in the PL spectra of the as-prepared Eu-doped ZnS QDs and the bands at ~590, ~618 and ~695 nm were assigned to transitions from (5)D0 to (7)F1, (7)F2 and (7)F4, respectively. Quenching of the ZnS bandgap PL and enhancement of the Eu dopant PL were observed with increasing Eu(3+) doping concentration, and also, the excitation spectra for Eu emission (618 nm) were similar to the typical excitonic features of the ZnS host. These spectroscopic results, as well as the XRD and EDS data, demonstrated that Eu(3+) ions were incorporated in the ZnS host rather than just on the surface, and the Eu dopant PL was derived from energy transfer from the QD host to Eu(3+) rather than direct excitation of Eu(3+). By surface passivation, the sharp Eu emission was well-separated from the ZnS bandgap emission, which led to a good signal-to-noise ratio for more sensitive detection.
Collapse
Affiliation(s)
- Yongbo Wang
- School of Chemical Engineering, Northwest University, No. 229 Taibai North Road, Xi'an, Shaanxi, 710069, People's Republic of China
| | | | | | | | | |
Collapse
|
21
|
Cao S, Li C, Wang L, Shang M, Wei G, Zheng J, Yang W. Long-lived and well-resolved Mn²⁺ ion emissions in CuInS-ZnS quantum dots. Sci Rep 2014; 4:7510. [PMID: 25515207 PMCID: PMC5378940 DOI: 10.1038/srep07510] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 11/14/2014] [Indexed: 12/28/2022] Open
Abstract
CuInS2 (CIS) quantum dots (QDs) have tunable photoluminescence (PL) behaviors in the visible and near infrared spectral range with markedly lower toxicity than the cadmium-based counterparts, making them very promising applications in light emitting and solar harvesting. However, there still remain material- and fabrication- related obstacles in realizing the high-performance CIS-based QDs with well-resolved Mn2+d-d emission, long emission lifetimes as well as high efficiencies. Here, we demonstrate the growth of high-quality Mn2+-doped CuInS-ZnS (CIS-ZnS) QDs based on a multi-step hot-injection strategy. The resultant QDs exhibit a well-resolved Mn2+d-d emission with a high PL quantum yield (QY) up to 66% and an extremely long excited state lifetime up to ~3.78 ms, which is nearly two times longer than the longest one of “green” QDs ever reported. It is promising that the synthesized Mn2+-doped CIS-ZnS QDs might open new doors for their practical applications in bioimaging and opto/electronic devices.
Collapse
Affiliation(s)
- Sheng Cao
- 1] School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China [2] Institute of Materials, Ningbo University of Technology, Ningbo 315016, China
| | - Chengming Li
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Lin Wang
- Institute of Materials, Ningbo University of Technology, Ningbo 315016, China
| | - Minghui Shang
- Institute of Materials, Ningbo University of Technology, Ningbo 315016, China
| | - Guodong Wei
- Institute of Materials, Ningbo University of Technology, Ningbo 315016, China
| | - Jinju Zheng
- Institute of Materials, Ningbo University of Technology, Ningbo 315016, China
| | - Weiyou Yang
- Institute of Materials, Ningbo University of Technology, Ningbo 315016, China
| |
Collapse
|
22
|
Debnath T, Maity P, Maiti S, Ghosh HN. Electron Trap to Electron Storage Center in Specially Aligned Mn-Doped CdSe d-Dot: A Step Forward in the Design of Higher Efficient Quantum-Dot Solar Cell. J Phys Chem Lett 2014; 5:2836-42. [PMID: 26278087 DOI: 10.1021/jz5012719] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Specially aligned surface-accumulated Mn-doped CdSe (MnCdSe) quantum dots (QDs) have been synthesized to study the effect of dopant atom on charge-carrier dynamics in QD materials. EPR studies suggest that the (4)T1 state of Mn(2+) lies above the conduction band of CdSe, and as a result no Mn-luminescence was observed from MnCdSe. Femtosecond transient absorption studies suggest that Mn atom introduces structural defects in surface-doped CdSe, which acts as electron trap center in doped QD for the photoexcited electron. Bromo-pyrogallol red (Br-PGR) were found to form strong charge-trasfer complex with both CdSe and MnCdSe QDs. Charge separation in both the CdSe/Br-PGR and MnCdSe/Br-PGR composites was found to take place in three different pathways by transferring the photoexcited hole of CdSe/MnCdSe QDs to Br-PGR, electron injection from photoexcited Br-PGR to the QDs, and direct electron transfer from the HOMO of Br-PGR to the conduction band of both the QDs. Hole-transfer dynamics are found to be quite similar (∼1.1 to 1.3 ps) for both of the systems and found to be independent of Mn doping. However, charge recombination dynamics was found to be much slower in the MnCdSe/Br-PGR system as compared with that in the CdSe/Br-PGR system, which confirms that the Mn dopant act as the electron storage center. As a consequence, the MnCdSe/Br-PGR system can be used as a better super sensitizer in quantum-dot-sensitized solar cell to increase efficiency further.
Collapse
|