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Vasylchenko I, Grill R, Betušiak M, Belas E, Praus P, Moravec P, Höschl P. In and Al Schottky Contacts Comparison on P-Type Chlorine-Doped CdTe. Sensors (Basel) 2021; 21:s21082783. [PMID: 33920852 PMCID: PMC8071194 DOI: 10.3390/s21082783] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/11/2021] [Accepted: 04/12/2021] [Indexed: 11/16/2022]
Abstract
The performance of the CdTe radiation detectors heavily relies on the method of contact preparation. A convenient research method addressing this problem is the laser-induced transient current technique. In this paper, we compare the performance of two CdTe crystals which underwent different metallization processes. We showed that appropriately designed Au/Al contacts induce much less bulk polarization than commercial Pt/In electrodes under the same working conditions and can thus provide a convenient alternative to the industry standard. The comparison was based on the monitoring of the time-dependent sensor polarization measuring transient currents excited by above-bandgap laser illumination complemented by the Am 241 gamma spectroscopy. The theoretical analysis of current waveforms and radiation spectra enabled us to determine the charge carrier mobility, mobility-lifetime products of electrons and holes, and temporal and bias dependence of the space charge formation.
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Musiienko A, Pipek J, Praus P, Brynza M, Belas E, Dryzhakov B, Du MH, Ahmadi M, Grill R. Deciphering the effect of traps on electronic charge transport properties of methylammonium lead tribromide perovskite. Sci Adv 2020; 6:6/37/eabb6393. [PMID: 32917707 PMCID: PMC7486106 DOI: 10.1126/sciadv.abb6393] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 07/29/2020] [Indexed: 05/17/2023]
Abstract
Halide perovskites have undergone remarkable developments as highly efficient optoelectronic materials for a variety of applications. Several studies indicated the critical role of defects on the performance of perovskite devices. However, the parameters of defects and their interplay with free charge carriers remain unclear. In this study, we explored the dynamics of free holes in methylammonium lead tribromide (MAPbBr3) single crystals using the time-of-flight (ToF) current spectroscopy. By combining ToF spectroscopy and Monte Carlo simulation, three energy states were detected in the bandgap of MAPbBr3 In addition, we found the trapping and detrapping rates of free holes ranging from a few microseconds to hundreds of microseconds. Contrary to previous studies, we revealed a strong detrapping activity of traps. We showed that these traps substantially affect the transport properties of MAPbBr3, including mobility and mobility-lifetime product. Our results provide an insight on charge transport properties of perovskite semiconductors.
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Affiliation(s)
- Artem Musiienko
- Charles University, Faculty of Mathematics and Physics, Institute of Physics, Ke Karlovu 5, CZ-121 16 Prague 2, Czech Republic.
| | - Jindřich Pipek
- Charles University, Faculty of Mathematics and Physics, Institute of Physics, Ke Karlovu 5, CZ-121 16 Prague 2, Czech Republic
| | - Petr Praus
- Charles University, Faculty of Mathematics and Physics, Institute of Physics, Ke Karlovu 5, CZ-121 16 Prague 2, Czech Republic
| | - Mykola Brynza
- Charles University, Faculty of Mathematics and Physics, Institute of Physics, Ke Karlovu 5, CZ-121 16 Prague 2, Czech Republic
| | - Eduard Belas
- Charles University, Faculty of Mathematics and Physics, Institute of Physics, Ke Karlovu 5, CZ-121 16 Prague 2, Czech Republic
| | - Bogdan Dryzhakov
- Joint Institute for Advanced Materials, Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Mao-Hua Du
- Oak Ridge National Laboratory, Materials Science and Technology Division, Oak Ridge, TN 37831, USA
| | - Mahshid Ahmadi
- Joint Institute for Advanced Materials, Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA.
| | - Roman Grill
- Charles University, Faculty of Mathematics and Physics, Institute of Physics, Ke Karlovu 5, CZ-121 16 Prague 2, Czech Republic
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Vasylchenko I, Grill R, Belas E, Praus P, Musiienko A. Charge Sharing in (CdZn)Te Pixel Detector Characterized by Laser-Induced Transient Currents. Sensors (Basel) 2019; 20:s20010085. [PMID: 31877830 PMCID: PMC6983191 DOI: 10.3390/s20010085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/12/2019] [Accepted: 12/19/2019] [Indexed: 12/03/2022]
Abstract
Performance of the (CdZn)Te pixelated detectors heavily relies on the quality of the underlying material. Modern laser-induced transient current technique addresses this problem as a convenient tool for characterizing the associated charge distribution. In this paper, we investigated the charge sharing phenomenon in (CdZn)Te pixel detector as a function of the charge collected on adjacent pixels. The current transients were generated in the defined 4 mm2 spots using 660 nm laser illumination. Waveforms measured on the pixel of interest and its surroundings were used to build the maps of the collected charge at different biases. The detailed study of the maps allowed us to distinguish the charge sharing region, the region with a defect, and the finest part in terms of the performance part of the pixelated anode. We observed the principal inhomogeneity complicating the assignment of the illuminated spot to the nearest pixel.
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Franc J, Šedivý L, Belas E, Bugár M, Zázvorka J, Pekárek J, Uxa Š, Höschl P, Fesh R. Melt growth and post-grown annealing of semiinsulating (CdZn)Te by vertical gradient freeze method. Cryst Res Technol 2013. [DOI: 10.1002/crat.201300006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Rafiei R, Boardman D, Reinhard MI, Sarbutt A, Kim K, Watt GC, Uxa S, Prokopovich DA, Belas E, Bolotnikov AE, James RB. Charge transport properties of CdMnTe radiation detectors. EPJ Web of Conferences 2012. [DOI: 10.1051/epjconf/20123502005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Turkevych I, Grill R, Franc J, Höschl P, Belas E, Moravec P, Fiederle M, Benz KW. Preparation of semi-insulating CdTe doped with group IV elements by post growth annealing. Cryst Res Technol 2003. [DOI: 10.1002/crat.200310033] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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