Charge Carrier Recombination Dynamics in MAPb(Br_xCl_1–x)₃ Single Crystals

Abstract

Understanding carrier recombination processes in MAPb(Br x Cl1–x )3 crystals is essential for their photoelectrical applications. In this work, carrier recombination dynamics in MAPb(Br x Cl1–x )3 single crystals were studied by steady-state photoluminescence (PL), time-resolved photoluminescence (TRPL), and time-resolved microwave photoconductivity (TRMC). By comparing TRPL and TRMC, we find TRPL of MAPb(Br x Cl1–x )3 (x < 0.98) single crystals is dominated by a hole trapping process while the long-lived component of TRMC is dominated by an electron trapping process. We also find both electron and hole trapping rates of MAPb(Br x Cl1−x )3 (x < 0.98) crystals decrease with an increase in Br content. A temperature-dependent PL study shows there are shallow trap states besides the deep level trap states in the MAPb(Br0.82Cl0.18)3 crystal. The activation energy for holes in shallow trap states detrapped into the valence band is ∼0.1 eV, while the activation energy for free holes to be trapped into deep trap states is ∼0.4 eV. This work provides insight into carrier recombination processes in MAPb(Br x Cl1–x )3 single crystals.

Enhanced Higher Harmonic Generation in Modified MAPbBr3–xClx Single Crystal by Additive Engineering

“…19 Although PSC growth techniques have rapidly improved the surface quality 20,21 and crystals' performance, stability issues like phase segregation, 22−24 rapid material degradation, 25,26 hysteresis, 27, 28 and environmental factors such as moisture and heat are the challenges that hamper the commercialization of these materials. 29,30 Phase segregation has been explained by using a continuous wave (CW) diode laser in the case of microcrystalline thin films. Additionally, forming formamidinium and cesium lead iodide solid-state alloys stabilized the perovskite structures by tuning the tolerance factor.…”

“…Some crystallization methods include the inverse temperature method (ITC), temperature-lowering method, top-seeded crystallization method, antisolvent vapor assistant method (AVC), Bridgman growth method, low-temperature gradient crystallization, cavitations triggered asymmetrical crystallization, and room-temperature liquid diffused separation induced crystallization (LDSC) . Although PSC growth techniques have rapidly improved the surface quality , and crystals’ performance, stability issues like phase segregation, − rapid material degradation, , hysteresis, , and environmental factors such as moisture and heat are the challenges that hamper the commercialization of these materials. , …”