- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Particle size effects of tetrahedron-shaped Ag3PO4 photocatalyst on water-oxidation activity and carrier recombination dynamics
摘要： We investigated photocatalytic water-oxidation performance of tetrahedron-shaped silver phosphate (Ag3PO4) crystals with various particle sizes. The performance was clearly influenced by the particle size. The maximum activity was found for the particle with a tetrahedron edge with 1.5 μm length, which showed the highest rate of oxygen evolution. A series of analysis against time-resolved diffuse reflection spectra of the powder samples reveals that not only carrier recombination dynamic but also photoexcited carrier density can play important roles in the water oxidation. Our finding should contribute to give one of the basic ideas when designing semiconductor photocatalysts for water splitting.
关键词： Silver phosphate,Photocatalytic water oxidation,Global analysis,Carrier dynamics
更新于2025-11-19 16:51:07
-
Ultrafast Interfacial Charge Transfer of Cesium Lead Halide Perovskite Films CsPbX3 (X = Cl, Br, I) with Different Halogen Mixing
摘要： Understanding the interfacial charge transfer of the photoinduced transients of all-inorganic cesium lead halide perovskites (CsPbX3; X = Cl, Br, I) is critical for their photovoltaic applications. Ultrafast dynamics can provide comprehensive information about the transient behavior of the carriers and their transfer mechanism in the materials. In this work, the interfacial charge transfer of CsPbX3 films assembled with TiO2 with different halogen doping ratios was studied using femtosecond transient absorption (TA) spectroscopy combined with global analysis. Four subsequent decay processes after photoexcitation were obtained, including hot carrier cooling, free exciton forming, electron transfer, and charge recombination. The results indicate that the time constant of the interfacial electron transfer varies with the location of the trap state of these perovskites and the relative energy of CBs in the perovskite and TiO2 and that the time constant of the charge recombination can be attributed to the electron–hole interactions. These interpretations are supported by calculations based on first-principles density functional theory (DFT). Greater iodine doping in such perovskite CsPbX3/TiO2 systems increases the time constants of the electron transfer and charge recombination, which suggests that all-inorganic perovskite CsPbX3 with a high iodine content is favorable for improving the power conversion efficiency of solar cells.
关键词： cesium lead halide perovskite,transient absorption,global analysis,interfacial charge transfer
更新于2025-09-23 15:21:01
-
Bismuth doped lead-free two-dimensional tin based halide perovskite single crystals
摘要： Heterovalent-metal doping is an efficient tool to tune the optoelectronic properties of the famous halide perovskites. Previous studies have focused on the heterovalent-doping in three-dimensional (3D) halide perovskites. However, there is a lack of such doping in two-dimensional perovskites which possess unique optoelectronic properties and improved chemical stability as compared to 3D analogues. Here, we present successful doping of Bismuth into the lattice of lead-free, two-dimensional perovskite PEA2SnBr4 single crystals. Structural characterizations demonstrate that the doped crystals possess identical crystal structure and layered morphology with the pristine one. Intriguingly, we find the PL peak and spectral shape can be tailored by tuning the concentration of Bi dopants. Femtosecond transient absorption spectroscopy is performed to understand the underlying mechanism related to tunable PL behaviors, and a clear picture of the Bismuth-doping impact is provided.
关键词： Global analysis fit,Femtosecond transient absorption spectra,Self-trapped excitons,Photoluminescence,Heterovalent-metal doping
更新于2025-09-04 15:30:14