scholarly journals Are Shockley-Read-Hall and ABC models valid for lead halide perovskites?

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alexander Kiligaridis ◽  
Pavel A. Frantsuzov ◽  
Aymen Yangui ◽  
Sudipta Seth ◽  
Jun Li ◽  
...  

AbstractMetal halide perovskites are an important class of emerging semiconductors. Their charge carrier dynamics is poorly understood due to limited knowledge of defect physics and charge carrier recombination mechanisms. Nevertheless, classical ABC and Shockley-Read-Hall (SRH) models are ubiquitously applied to perovskites without considering their validity. Herein, an advanced technique mapping photoluminescence quantum yield (PLQY) as a function of both the excitation pulse energy and repetition frequency is developed and employed to examine the validity of these models. While ABC and SRH fail to explain the charge dynamics in a broad range of conditions, the addition of Auger recombination and trapping to the SRH model enables a quantitative fitting of PLQY maps and low-power PL decay kinetics, and extracting trap concentrations and efficacies. However, PL kinetics at high power are too fast and cannot be explained. The proposed PLQY mapping technique is ideal for a comprehensive testing of theories and applicable to any semiconductor.

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
O. Amora

Hybrid lead halide perovskites emerged at the beginning of 2010s decade as one of the most promising materials for photovoltaic applications. Easy and low-cost solution-based fabrication processes can be used, obtaining perovskite solar cells (PSCs) with efficiencies above 20%. However, there still are some major issues to overcome, like stabiliddty, and the general understanding of the recombination mechanisms resHybrid lead halide perovskites emerged at the beginning of 2010s decade as one of the most promising materials for photovoltaic applications. Easy and low-cost solution-based fabrication processes can be used, obtaining perovskite solar cells (PSCs) with efficiencies above 20%. However, there still are some major issues to overcome, like stability, and the general understanding of the recombination mechanisms results particularly puzzling. In this chapter, an analysis is provided on most recent research results about the different mechanisms, location and relationships of charge carrier recombination in PSCs. After introducing the theoretical framework, including the main transport equations and relations with luminescence techniques, the radiative and non-radiative natures of recombination are commented and compared in terms of main contributions. Also, the effects of changing the perovskite composition and morphology are surveyed. The location of the recombination processes, whether in the bulk material or towards the interface, are tackled, as well as related features with the current-voltage hysteresis. On the latter, and along the complete chapter, the dual ionic-electronic conductivity of hybrid lead halide perovskites is particularly attended. ults particularly puzzling. In this chapter, an analysis is provided on most recent research results about the different mechanisms, location and relationships of charge carrier recombination in PSCs. After introducing the theoretical framework, including the main transport equations and relations with luminescence techniques, the radiative and non-radiative natures of recombination are commented and compared in terms of main contributions. Also, the effects of changing the perovskite composition and morphology are surveyed. The location of the recombination processes, whether in the bulk material or towards the interface, are tackled, as well as related features with the current-voltage hysteresis. On the latter, and along the complete chapter, the dual ionic-electronic conductivity of hybrid lead halide perovskites is particularly attended. ybrid lead halide perovskites emerged at the beginning of 2010s decade as one of the most promising materials for photovoltaic applications. Easy and low-cost solution-based fabrication processes can be used, obtaining perovskite solar cells (PSCs) with efficiencies above 20%. However, there still are some major issues to overcome, like stability, and the general understanding of the recombination mechanisms results particularly puzzling. In this chapter, an analysis is provided on most recent research results about the different mechanisms, location and relationships of charge carrier recombination in PSCs. After introducing the theoretical framework, including the main transport equations and relations with luminescence techniques, the radiative and non-radiative natures of recombination are commented and compared in terms of main contributions. Also, the effects of changing the perovskite composition and morphology are surveyed. The location of the recombination processes, whether in the bulk material or towards the interface, are tackled, as well as related features with the current-voltage hysteresis. On the latter, and along the complete chapter, the dual ionic-electronic conductivity of hybrid lead halide perovskites is particularly attended.


APL Materials ◽  
2014 ◽  
Vol 2 (8) ◽  
pp. 081513 ◽  
Author(s):  
Christian Wehrenfennig ◽  
Mingzhen Liu ◽  
Henry J. Snaith ◽  
Michael B. Johnston ◽  
Laura M. Herz

2016 ◽  
Vol 253 ◽  
pp. 11-40 ◽  
Author(s):  
Yi Yang ◽  
Ying Chih Pu ◽  
Yat Li ◽  
Jin Zhang

Titanium dioxide (TiO2) has been widely used as photoanodes in photoelectrochemical (PEC) water splitting. However, the typically high density of bandgap trap states results in fast charge carrier recombination and poor electrical conductivity, and thereby weak PEC performance. Rational creation of oxygen vacancy (Vo) in TiO2 has been demonstrated as an effective method to modify the electronic and optical properties, as well as improved PEC performance. Different strategies have been developed to fabricate oxygen deficient TiO2 photoanodes, such as hydrogen treatment, thermal annealing, electrochemical reduction, flame reduction, and chemical reduction. In conjunction with oxygen vacancy creation, doping of TiO2 with elements further enhances the PEC activity by introducing other bandgap states. Various techniques, including ultrafast laser spectroscopy, have been employed to probe the chemical nature and associated charge carrier dynamics of the bandgap states.


2019 ◽  
Vol 29 (35) ◽  
pp. 1902656 ◽  
Author(s):  
Leonardo R. V. Buizza ◽  
Timothy W. Crothers ◽  
Zhiping Wang ◽  
Jay B. Patel ◽  
Rebecca L. Milot ◽  
...  

2018 ◽  
Vol 9 (21) ◽  
pp. 6312-6320 ◽  
Author(s):  
Zhaoning Song ◽  
Niraj Shrestha ◽  
Suneth C. Watthage ◽  
Geethika K. Liyanage ◽  
Zahrah S. Almutawah ◽  
...  

2019 ◽  
Vol 119 (20) ◽  
pp. 11007-11019 ◽  
Author(s):  
Dane W. deQuilettes ◽  
Kyle Frohna ◽  
David Emin ◽  
Thomas Kirchartz ◽  
Vladimir Bulovic ◽  
...  

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhengyuan Qin ◽  
Chunfeng Zhang ◽  
Lan Chen ◽  
Xiaoyong Wang ◽  
Min Xiao

Sn doping is established as an effective approach to promote the light emission properties in in two-dimensional lead-halide perovskites. However, the effect on the charge carrier dynamics is largely unexplored. In this work, we conduct terahertz spectroscopy to study the effects of Sn doping on the charge dynamics in the two-dimensional perovskites PEA2SnxPb1–xI4 (PEA = phenethylammonium) with different doping levels. The spectral dispersion analysis suggests that the early-stage dynamics with lifetime of ∼ 2 ps is contributed by both the transport of hot charge carriers and the polarizability of hot excitons. The long-lived component of first-order charge carrier recombination is dramatically improved when Sn doping increases, which is ascribed to the equilibrium between charge carriers and excitons with smaller bind energies in the higher-level Sn-doped samples. The finding in this work suggests Sn doping is an effective approach to optimize the charge carrier transport in 2D perovskite for potential optoelectronic applications.


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