Optical Visualization of Photoexcitation Diffusion in All-Inorganic Perovskite at High Temperature

Abstract

All-inorganic halide perovskites are promising candidates for optoelectronic and photovoltaic devices because of their good thermal stability and remarkable optoelectronic properties. Among those properties, carrier transport properties are critical as they inherently dominate the device performance. The transport properties of perovskites have been widely studied at room and lower temperatures, but their high-temperature (i.e., tens of degrees above room temperature) characteristics are not fully understood. Here, the photoexcitation diffusion is optically visualized by transient photoluminescence microscopy (TPLM), through which the temperature-dependent transport characteristics from room temperature to 80 °C are studied in all-inorganic CsPbBr3 single-crystalline microplates. We reveal the decreasing trend of diffusion coefficient and the almost unchanged trend of diffusion length when heating the sample to high temperature. The phonon scattering in combination with the variation of effective mass is proposed for the explanation of the temperature-dependent diffusion behavior.

Long Exciton Diffusion Length in High Mobility Emissive Organic Semiconductor

“…Exciton dynamics plays a critical role for the photoelectric conversion process, determining the performance of optoelectronic devices. To explore the exciton diffusion capabilities of BPTTE, the spatiotemporal photoexcitation dynamics of a single BPTTE crystal were characterized using the TPLM technique, as depicted in Figure a . When excited by a 405 nm laser, singlet excitons were generated and migrated across the surface of the BPTTE single crystal during its fluorescence lifetime.…”

“…To explore the exciton diffusion capabilities of BPTTE, the spatiotemporal photoexcitation dynamics of a single BPTTE crystal were characterized using the TPLM technique, as depicted in Figure 4a. 42 When excited by a 405 nm laser, singlet excitons were generated and migrated across the surface of the BPTTE single crystal during its fluorescence lifetime. The typical spatial and temporal evolutions of the fluorescence intensity distribution at each time slice were normalized, as shown in Figure 4b.…”

A‐site Cation Exchange Enables a High‐performance CsPbBr3 Photodetector for Laser Eavesdropping Systems

“…[12][13][14][15][16] Cs-based all-inorganic perovskite, especially CsPbBr 3 , exhibits superior air stability and thermal stability. [17][18][19][20][21][22][23] But the equally tricky thing is that the three-dimensional (3D) skeleton structure of cubic-phase CsPbI 3 composed of Pb-I octahedron cannot stay stable, and it will rapidly decline from perovskite phase (𝛼 phase) to non-perovskite phase (𝛿 phase), resulting in the poor phase stability of CsPbI 3 at room temperature. [24][25][26] As for CsPbCl 3 and CsPbBr 3 , it is difficult to synthesize dense and high-quality perovskite films due to their limited solubility in traditional solvents.…”