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Boschi A, Kovtun A, Liscio F, Xia Z, Kim KH, Avila SL, De Simone S, Mussi V, Barone C, Pagano S, Gobbi M, Samorì P, Affronte M, Candini A, Palermo V, Liscio A. Mesoscopic 3D Charge Transport in Solution-Processed Graphene-Based Thin Films: A Multiscale Analysis. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2303238. [PMID: 37330652 DOI: 10.1002/smll.202303238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 06/05/2023] [Indexed: 06/19/2023]
Abstract
Graphene and related 2D material (GRM) thin films consist of 3D assembly of billions of 2D nanosheets randomly distributed and interacting via van der Waals forces. Their complexity and the multiscale nature yield a wide variety of electrical characteristics ranging from doped semiconductor to glassy metals depending on the crystalline quality of the nanosheets, their specific structural organization ant the operating temperature. Here, the charge transport (CT) mechanisms are studied that are occurring in GRM thin films near the metal-insulator transition (MIT) highlighting the role of defect density and local arrangement of the nanosheets. Two prototypical nanosheet types are compared, i.e., 2D reduced graphene oxide and few-layer-thick electrochemically exfoliated graphene flakes, forming thin films with comparable composition, morphology and room temperature conductivity, but different defect density and crystallinity. By investigating their structure, morphology, and the dependence of their electrical conductivity on temperature, noise and magnetic-field, a general model is developed describing the multiscale nature of CT in GRM thin films in terms of hopping among mesoscopic bricks, i.e., grains. The results suggest a general approach to describe disordered van der Waals thin films.
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Affiliation(s)
- Alex Boschi
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, (CNR-ISOF), via Gobetti 101, Bologna, 40129, Italy
- Istituto Italiano di Tecnologia, IIT - CNI, Laboratorio NEST, piazza S. Silvestro 12, Pisa, 56127, Italy
| | - Alessandro Kovtun
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, (CNR-ISOF), via Gobetti 101, Bologna, 40129, Italy
| | - Fabiola Liscio
- Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi, (CNR-IMM) - Bologna Unit, via Gobetti 101, Bologna, 40129, Italy
| | - Zhenyuan Xia
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, (CNR-ISOF), via Gobetti 101, Bologna, 40129, Italy
- Chalmers University of Technology, Department of Industrial and Materials Science, Kemivägen 9, Gothenburg, 41296, Sweden
| | - Kyung Ho Kim
- Chalmers University of Technology, Department of Microtechnology and Nanoscience, Kemivägen 9, Gothenburg, 41296, Sweden
- Physics Department, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK
| | - Samuel Lara Avila
- Chalmers University of Technology, Department of Microtechnology and Nanoscience, Kemivägen 9, Gothenburg, 41296, Sweden
| | - Sara De Simone
- Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi, (CNR-IMM) - Roma Unit, via del Fosso del Cavaliere 100, Roma, 00133, Italy
- Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi, (CNR-IMM) - Lecce Unit, SP Lecce-Monteroni km 1,200, Lecce, 73100, Italy
| | - Valentina Mussi
- Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi, (CNR-IMM) - Roma Unit, via del Fosso del Cavaliere 100, Roma, 00133, Italy
| | - Carlo Barone
- Dipartimento di Fisica "E.R. Caianiello", Università degli Studi di Salerno, Via Giovanni Paolo II 132, Fisciano, SA, 84084, Italy
- CNR-SPIN Salerno and INFN Gruppo Collegato di Salerno, c/o Università degli Studi di Salerno, Fisciano, SA, 84084, Italy
| | - Sergio Pagano
- Dipartimento di Fisica "E.R. Caianiello", Università degli Studi di Salerno, Via Giovanni Paolo II 132, Fisciano, SA, 84084, Italy
- CNR-SPIN Salerno and INFN Gruppo Collegato di Salerno, c/o Università degli Studi di Salerno, Fisciano, SA, 84084, Italy
| | - Marco Gobbi
- CIC nanoGUNE, Tolosa Hiribidea 76, Donostia - San Sebastian, E-20018, Spain
| | - Paolo Samorì
- Université de Strasbourg, CNRS, ISIS, 8 allée Gaspard Monge, Strasbourg, 67000, France
| | - Marco Affronte
- Dipartimento di Scienze Fisiche, Informatiche e Matematiche (FIM), via Giuseppe Campi 213/a, Modena, 41125, Italy
| | - Andrea Candini
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, (CNR-ISOF), via Gobetti 101, Bologna, 40129, Italy
| | - Vincenzo Palermo
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, (CNR-ISOF), via Gobetti 101, Bologna, 40129, Italy
| | - Andrea Liscio
- Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi, (CNR-IMM) - Roma Unit, via del Fosso del Cavaliere 100, Roma, 00133, Italy
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Landi G, Granata V, Germano R, Pagano S, Barone C. Low-Power and Eco-Friendly Temperature Sensor Based on Gelatin Nanocomposite. NANOMATERIALS 2022; 12:nano12132227. [PMID: 35808063 PMCID: PMC9268468 DOI: 10.3390/nano12132227] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/23/2022] [Accepted: 06/27/2022] [Indexed: 11/29/2022]
Abstract
An environmentally-friendly temperature sensor has been fabricated by using a low-cost water-processable nanocomposite material based on gelatin and graphene. The temperature dependence of the electrochemical properties has been investigated by using cyclic voltammetry, chronopotentiometry and impedance spectroscopy measurements. The simple symmetric device, composed of a sandwich structure between two metal foils and a printable graphene–gelatin blend, exhibits a dependence on the open-circuit voltage in a range between 260 and 310 K. Additionally, at subzero temperature, the device is able to detect the ice/frost formation. The thermally-induced phenomena occur at the electrode/gel interface with a bias current of a few tens of μA. The occurrence of dissociation reactions within the sensor causes limiting-current phenomena in the gelatin electrolyte. A detailed model describing the charge carrier accumulation, the faradaic charge transfer and diffusion processes within the device under the current-controlled has been proposed. In order to increase the cycle stability of the temperature sensor and reduce its voltage drift and offset of the output electrical signal, a driving circuit has been designed. The eco-friendly sensor shows a temperature sensitivity of about −19 mV/K, long-term stability, fast response and low-power consumption in the range of microwatts suitable for environmental monitoring for indoor applications.
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Affiliation(s)
- Giovanni Landi
- ENEA, Casaccia Research Center, Via Anguillarese 301, 00123 Rome, Italy
- Correspondence: (G.L.); (C.B.)
| | - Veronica Granata
- Dipartimento di Fisica “E.R. Caianiello”, Università degli Studi di Salerno, 84084 Fisciano, Italy; (V.G.); (S.P.)
- INFN Gruppo Collegato di Salerno, c/o Università degli Studi di Salerno, 84084 Fisciano, Italy
| | - Roberto Germano
- PROMETE Srl, CNR Spin off, P.le V. Tecchio, 45, 80125 Naples, Italy;
| | - Sergio Pagano
- Dipartimento di Fisica “E.R. Caianiello”, Università degli Studi di Salerno, 84084 Fisciano, Italy; (V.G.); (S.P.)
- INFN Gruppo Collegato di Salerno, c/o Università degli Studi di Salerno, 84084 Fisciano, Italy
- CNR-SPIN, c/o Università degli Studi di Salerno, 84084 Fisciano, Italy
| | - Carlo Barone
- Dipartimento di Fisica “E.R. Caianiello”, Università degli Studi di Salerno, 84084 Fisciano, Italy; (V.G.); (S.P.)
- INFN Gruppo Collegato di Salerno, c/o Università degli Studi di Salerno, 84084 Fisciano, Italy
- CNR-SPIN, c/o Università degli Studi di Salerno, 84084 Fisciano, Italy
- Correspondence: (G.L.); (C.B.)
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High-performance photonic transformers for DC voltage conversion. Nat Commun 2021; 12:4684. [PMID: 34344884 PMCID: PMC8333049 DOI: 10.1038/s41467-021-24955-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 07/12/2021] [Indexed: 11/21/2022] Open
Abstract
Direct current (DC) converters play an essential role in electronic circuits. Conventional high-efficiency DC voltage converters, especially step-up type, rely on switching operation, where energy is periodically stored within and released from inductors and/or capacitors connected in a variety of circuit topologies. Since these energy storage components, especially inductors, are fundamentally difficult to scale down, miniaturization of switching converters proves challenging. Furthermore, the resulting switching currents produce significant electromagnetic noise. To overcome the limitations of switching converters, photonic transformers, where voltage conversion is achieved through light emission and detection processes, have been demonstrated. However, the demonstrated efficiency is significantly below that of the switching converter. Here we perform a detailed balance analysis and show that with a monolithically integrated design that enables efficient photon transport, the photonic transformer can operate with a near-unity conversion efficiency and high voltage conversion ratio. We validate the theory with a transformer constructed with off-the-shelf discrete components. Our experiment showcases near noiseless operation and a voltage conversion ratio that is significantly higher than obtained in previous photonic transformers. Our findings point to the possibility of a high-performance optical solution to miniaturizing DC power converters and improving the electromagnetic compatibility and quality of electrical power. Conventional DC-DC converters rely on switching operations and energy storing components which face both noise and scaling difficulties. Here, the authors present an alternative design for a DC-to-DC converter based on closely coupled LEDs and photovoltaic cells, which exhibits high efficiency, low noise, and miniaturizability.
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Relaxation processes in silicon heterojunction solar cells probed via noise spectroscopy. Sci Rep 2021; 11:13238. [PMID: 34168278 PMCID: PMC8225850 DOI: 10.1038/s41598-021-92866-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 06/14/2021] [Indexed: 11/29/2022] Open
Abstract
We have employed state-of-the-art cross-correlation noise spectroscopy (CCNS) to study carrier dynamics in silicon heterojunction solar cells (SHJ SCs). These cells were composed of a light absorbing n-doped monocrystalline silicon wafer contacted by passivating layers of i-a-Si:H and doped a-Si:H selective contact layers. Using CCNS, we are able to resolve and characterize four separate noise contributions: (1) shot noise with Fano factor close to unity due to holes tunneling through the np-junction, (2) a 1/f term connected to local potential fluctuations of charges trapped in a-Si:H defects, (3) generation-recombination noise with a time constant between 30 and 50 μs and attributed to recombination of holes at the interface between the ITO and n-a-Si:H window layer, and (4) a low-frequency generation-recombination term observed below 100 K which we assign to thermal emission over the ITO/ni-a-Si:H interface barrier. These results not only indicate that CCNS is capable of reveling otherwise undetectable relaxation process in SHJ SCs and other multi-layer devices, but also that the technique has a spatial selectivity allowing for the identification of the layer or interface where these processes are taking place.
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Abstract
Electric noise spectroscopy is a non-destructive and a very sensitive method for studying the dynamic behaviors of the charge carriers and the kinetic processes in several condensed matter systems, with no limitation on operating temperatures. This technique has been extensively used to investigate several perovskite compounds, manganese oxides (La1−xSrxMnO3, La0.7Ba0.3MnO3, and Pr0.7Ca0.3MnO3), and a double perovskite (Sr2FeMoO6), whose properties have recently attracted great attention. In this work are reported the results from a detailed electrical transport and noise characterizations for each of the above cited materials, and they are interpreted in terms of specific physical models, evidencing peculiar properties, such as quantum interference effects and charge density waves.
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Kumar A, Bansode U, Ogale S, Rahman A. Understanding the thermal degradation mechanism of perovskite solar cells via dielectric and noise measurements. NANOTECHNOLOGY 2020; 31:365403. [PMID: 32470953 DOI: 10.1088/1361-6528/ab97d4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Long term stability is a major obstacle to the success of perovskite solar cell (PSC) photovoltaic technology. PSC performance deteriorates significantly in the presence of humidity, oxygen and exposure to UV light and heat. Here the change in charge transport properties of PSC with temperature and the associated significant drop in device performance at high temperature have been investigated. The latter is shown to be primarily due to an increase in charge carrier recombination, which impacts the open-circuit voltage. To understand the pathway of temperature-induced degradation, low-frequency 1/f noise characteristics, and the capacitance-frequency, as well as capacitance-voltage characteristics have been investigated under various conditions. The results show that at high operating temperature accumulation of ions and charge carriers at the interface increase the surface recombination. Aging experiments at different temperatures show high stability of PSCs up to temperature <70 °C, but a drastic, irreversible degradation occurs at higher temperature (≥80 °C). Low-frequency 1/f noise study revealed that the magnitude of normalized noise in degraded perovskite solar cells is four orders of magnitude higher than the pristine device. This study shows the power of low-frequency noise measurement technique as a highly sensitive non-invasive tool to study the degradation mechanism of PSCs.
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Affiliation(s)
- Ankit Kumar
- Department of Physics and Centre for Energy Science, Indian Institute of Science Education and Research (IISER)-Pune, Pune, Maharashtra 411008 India
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Cirillo C, Barone C, Bradshaw H, Urban F, Di Bernardo A, Mauro C, Robinson JWA, Pagano S, Attanasio C. Magnetotransport and magnetic properties of amorphous [Formula: see text] thin films. Sci Rep 2020; 10:13693. [PMID: 32792527 PMCID: PMC7426968 DOI: 10.1038/s41598-020-70646-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/23/2020] [Indexed: 11/08/2022] Open
Abstract
[Formula: see text] is an intermetallic compound with a bulk Curie temperature ([Formula: see text]) of 6-13 K. While existing studies have focused on [Formula: see text] crystals, amorphous thin-films of [Formula: see text] are potentially important since they would be magnetically soft without magnetocrystalline anisotropy, meaning that small external magnetic fields could reverse the direction of their magnetization. Here, we report [Formula: see text] thin-films with a thickness in the 5-200 nm range, deposited by DC magnetron sputtering onto Si(100). Films are amorphous with a weak temperature-dependent resistivity with values ranging between 150 and 300 [Formula: see text] cm. By means of noise spectroscopy, by analyzing the time-dependence of fluctuation-induced voltages, it is found that at low temperatures the resistance fluctuations are due to the Kondo effect. Volume magnetometry indicates [Formula: see text] K with a magnetic coercive field of 30 mT at 5 K for a 125-nm-thick film. The results are promising for the development of Ferromagnet(F)/Superconductor(S)/Ferromagnet(F) pseudo spin-valve devices based on amorphous [Formula: see text] thin films.
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Affiliation(s)
- Carla Cirillo
- CNR-SPIN, c/o Università degli Studi di Salerno, 84084 Fisciano, SA Italy
- Dipartimento di Fisica “E. R. Caianiello”, Università degli Studi di Salerno, 84084 Fisciano, SA Italy
| | - Carlo Barone
- CNR-SPIN, c/o Università degli Studi di Salerno, 84084 Fisciano, SA Italy
- Dipartimento di Fisica “E. R. Caianiello”, Università degli Studi di Salerno, 84084 Fisciano, SA Italy
- INFN Gruppo Collegato di Salerno, c/o Università degli Studi di Salerno, 84084 Fisciano, SA Italy
| | - Harry Bradshaw
- Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS UK
| | - Francesca Urban
- CNR-SPIN, c/o Università degli Studi di Salerno, 84084 Fisciano, SA Italy
- Dipartimento di Fisica “E. R. Caianiello”, Università degli Studi di Salerno, 84084 Fisciano, SA Italy
- INFN Gruppo Collegato di Salerno, c/o Università degli Studi di Salerno, 84084 Fisciano, SA Italy
| | - Angelo Di Bernardo
- Fachbereich Physik, Universität Konstanz, Universitätsstraße 10, 78464 Konstanz, Germany
| | - Costantino Mauro
- Dipartimento di Fisica “E. R. Caianiello”, Università degli Studi di Salerno, 84084 Fisciano, SA Italy
| | - Jason W. A. Robinson
- Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS UK
| | - Sergio Pagano
- CNR-SPIN, c/o Università degli Studi di Salerno, 84084 Fisciano, SA Italy
- Dipartimento di Fisica “E. R. Caianiello”, Università degli Studi di Salerno, 84084 Fisciano, SA Italy
- INFN Gruppo Collegato di Salerno, c/o Università degli Studi di Salerno, 84084 Fisciano, SA Italy
| | - Carmine Attanasio
- CNR-SPIN, c/o Università degli Studi di Salerno, 84084 Fisciano, SA Italy
- Dipartimento di Fisica “E. R. Caianiello”, Università degli Studi di Salerno, 84084 Fisciano, SA Italy
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Iron-Based Superconducting Nanowires: Electric Transport and Voltage-Noise Properties. NANOMATERIALS 2020; 10:nano10050862. [PMID: 32365791 PMCID: PMC7711438 DOI: 10.3390/nano10050862] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/15/2020] [Accepted: 04/20/2020] [Indexed: 12/01/2022]
Abstract
The discovery of iron-based superconductors paved the way for advanced possible applications, mostly in high magnetic fields, but also in electronics. Among superconductive devices, nanowire detectors have raised a large interest in recent years, due to their ability to detect a single photon in the visible and infrared (IR) spectral region. Although not yet optimal for single-photon detection, iron-based superconducting nanowire detectors would bring clear advantages due to their high operating temperature, also possibly profiting of other peculiar material properties. However, there are several challenges yet to be overcome, regarding mainly: fabrication of ultra-thin films, appropriate passivation techniques, optimization of nano-patterning, and high-quality electrical contacts. Test nanowire structures, made by ultra-thin films of Co-doped BaFe2As2, have been fabricated and characterized in their transport and intrinsic noise properties. The results on the realized nanostructures show good properties in terms of material resistivity and critical current. Details on the fabrication and low temperature characterization of the realized nanodevices are presented, together with a study of possible degradation phenomena induced by ageing effects.
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Shen Q, Ng A, Ren Z, Gokkaya HC, Djurišić AB, Zapien JA, Surya C. Characterization of Low-Frequency Excess Noise in CH 3NH 3PbI 3-Based Solar Cells Grown by Solution and Hybrid Chemical Vapor Deposition Techniques. ACS APPLIED MATERIALS & INTERFACES 2018; 10:371-380. [PMID: 29094597 DOI: 10.1021/acsami.7b10091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this study, detailed investigations of low-frequency noise (LFN) characteristics of hybrid chemical vapor deposition (HCVD)- and solution-grown CH3NH3PbI3 (MAPI) solar cells are reported. It has been shown that LFN is a ubiquitous phenomenon observed in all semiconductor devices. It is the smallest signal that can be measured from the device; hence, systematic characterization of the LFN properties can be utilized as a highly sensitive nondestructive tool for the characterization of material defects in the device. It has been demonstrated that the noise power spectral densities of the devices are critically dependent on the parameters of the fabrication process, including the growth ambient of the perovskite layer and the incorporation of the mesoscopic structures in the devices. Our experimental results indicated that the LFN arises from a thermally activated trapping and detrapping process, resulting in the corresponding fluctuations in the conductance of the device. The results show that the presence of oxygen in the growth ambient of the HCVD process and the inclusion of an mp-TiO2 layer in the device structure are two important factors contributing to the substantial reduction in the density of the localized states in the MAPI devices. Furthermore, the lifetimes of the MAPI perovskite-based solar cells are strongly dependent on the material defect concentration. The degradation process is substantially more rapid for the devices with higher initial defect density compared to the devices prepared under optimized conditions and structure that exhibit substantially lower initial trap density.
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Affiliation(s)
- Qian Shen
- Department of Electronic and Information Engineering, The Hong Kong Polytechnic University , Kowloon, Hong Kong SAR
| | - Annie Ng
- Department of Electronic and Information Engineering, The Hong Kong Polytechnic University , Kowloon, Hong Kong SAR
| | - Zhiwei Ren
- Department of Electronic and Information Engineering, The Hong Kong Polytechnic University , Kowloon, Hong Kong SAR
| | - Huseyin Cem Gokkaya
- Department of Electronic and Information Engineering, The Hong Kong Polytechnic University , Kowloon, Hong Kong SAR
| | - Aleksandra B Djurišić
- Department of Physics, The University of Hong Kong , Pokfulam, Hong Kong Island, Hong Kong SAR
| | - Juan Antonio Zapien
- Department of Physics and Materials Science, City University of Hong Kong , Kowloon, Hong Kong SAR
| | - Charles Surya
- Department of Electronic and Information Engineering, The Hong Kong Polytechnic University , Kowloon, Hong Kong SAR
- School of Engineering, Nazarbayev University , 53 Kabanbay Batyr Avenue, Astana 010000, Kazakhstan
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Landi G, Neitzert HC, Barone C, Mauro C, Lang F, Albrecht S, Rech B, Pagano S. Correlation between Electronic Defect States Distribution and Device Performance of Perovskite Solar Cells. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2017; 4:1700183. [PMID: 29051860 PMCID: PMC5644241 DOI: 10.1002/advs.201700183] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 05/12/2017] [Indexed: 05/06/2023]
Abstract
In the present study, random current fluctuations measured at different temperatures and for different illumination levels are used to understand the charge carrier kinetics in methylammonium lead iodide CH3NH3PbI3-based perovskite solar cells. A model, combining trapping/detrapping, recombination mechanisms, and electron-phonon scattering, is formulated evidencing how the presence of shallow and deeper band tail states influences the solar cell recombination losses. At low temperatures, the observed cascade capture process indicates that the trapping of the charge carriers by shallow defects is phonon assisted directly followed by their recombination. By increasing the temperature, a phase modification of the CH3NH3PbI3 absorber layer occurs and for temperatures above the phase transition at about 160 K the capture of the charge carrier takes place in two steps. The electron is first captured by a shallow defect and then it can be either emitted or thermalize down to a deeper band tail state and recombines subsequently. This result reveals that in perovskite solar cells the recombination kinetics is strongly influenced by the electron-phonon interactions. A clear correlation between the morphological structure of the perovskite grains, the energy disorder of the defect states, and the device performance is demonstrated.
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Affiliation(s)
- Giovanni Landi
- Dipartimento di Ingegneria Industriale (DIIn)Università di SalernoVia Giovanni Paolo II 13284084Fisciano (SA)Italy
| | - Heinz Christoph Neitzert
- Dipartimento di Ingegneria Industriale (DIIn)Università di SalernoVia Giovanni Paolo II 13284084Fisciano (SA)Italy
| | - Carlo Barone
- Dipartimento di Fisica “E.R. Caianiello” and CNR‐SPIN SalernoUniversità di SalernoVia Giovanni Paolo II 13284084Fisciano (SA)Italy
| | - Costantino Mauro
- Dipartimento di Fisica “E.R. Caianiello” and CNR‐SPIN SalernoUniversità di SalernoVia Giovanni Paolo II 13284084Fisciano (SA)Italy
| | - Felix Lang
- Helmholtz‐Zentrum Berlin für Materialien und Energie GmbHInstitut für Silizium PhotovoltaikKekuléstr. 512489BerlinGermany
| | - Steve Albrecht
- Helmholtz‐Zentrum Berlin für Materialien und Energie GmbHInstitut für Silizium PhotovoltaikKekuléstr. 512489BerlinGermany
| | - Bernd Rech
- Helmholtz‐Zentrum Berlin für Materialien und Energie GmbHInstitut für Silizium PhotovoltaikKekuléstr. 512489BerlinGermany
| | - Sergio Pagano
- Dipartimento di Fisica “E.R. Caianiello” and CNR‐SPIN SalernoUniversità di SalernoVia Giovanni Paolo II 13284084Fisciano (SA)Italy
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11
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Probing Temperature-Dependent Recombination Kinetics in Polymer:Fullerene Solar Cells by Electric Noise Spectroscopy. ENERGIES 2017. [DOI: 10.3390/en10101490] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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Nobile MR, Valentino O, Morcom M, Simon GP, Landi G, Neitzert HC. The effect of the nanotube oxidation on the rheological and electrical properties of CNT/HDPE nanocomposites. POLYM ENG SCI 2017. [DOI: 10.1002/pen.24572] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Maria Rossella Nobile
- Department of Industrial Engineering - DIIn; Università di Salerno; Via Giovanni Paolo II 132 - 84084 Fisciano SA Italy
| | - Olga Valentino
- Department of Industrial Engineering - DIIn; Università di Salerno; Via Giovanni Paolo II 132 - 84084 Fisciano SA Italy
| | - Melanie Morcom
- Department of Materials Science and Engineering; Monash University; Clayton Victoria 3800 Australia
| | - George P. Simon
- Department of Materials Science and Engineering; Monash University; Clayton Victoria 3800 Australia
| | - Giovanni Landi
- Department of Industrial Engineering - DIIn; Università di Salerno; Via Giovanni Paolo II 132 - 84084 Fisciano SA Italy
| | - Heinz-Christoph Neitzert
- Department of Industrial Engineering - DIIn; Università di Salerno; Via Giovanni Paolo II 132 - 84084 Fisciano SA Italy
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13
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Unravelling the low-temperature metastable state in perovskite solar cells by noise spectroscopy. Sci Rep 2016; 6:34675. [PMID: 27703203 PMCID: PMC5050427 DOI: 10.1038/srep34675] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 09/16/2016] [Indexed: 11/08/2022] Open
Abstract
The hybrid perovskite methylammonium lead iodide CH3NH3PbI3 recently revealed its potential for the manufacturing of low-cost and efficient photovoltaic cells. However, many questions remain unanswered regarding the physics of the charge carrier conduction. In this respect, it is known that two structural phase transitions, occurring at temperatures near 160 and 310 K, could profoundly change the electronic properties of the photovoltaic material, but, up to now, a clear experimental evidence has not been reported. In order to shed light on this topic, the low-temperature phase transition of perovskite solar cells has been thoroughly investigated by using electric noise spectroscopy. Here it is shown that the dynamics of fluctuations detect the existence of a metastable state in a crossover region between the room-temperature tetragonal and the low-temperature orthorhombic phases of the perovskite compound. Besides the presence of a noise peak at this transition, a saturation of the fluctuation amplitudes is observed induced by the external DC current or, equivalently, by light exposure. This noise saturation effect is independent on temperature, and may represent an important aspect to consider for a detailed explanation of the mechanisms of operation in perovskite solar cells.
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