Band filling with free charge carriers in organonietal halide perovskites
Band filling with free charge carriers in organonietal halide perovskites
复制标题
DOI：
10.1038/nphoton.2014.171
复制
发表时间：
2014-09-01
期刊：
影响因子：
35
通讯作者：
Kamat, Prashant V.
中科院分区：
文献类型：
--
作者：
Manser, Joseph S.;Kamat, Prashant V.
半导体有机金属卤化物钙钛矿独特而有前景的性质使这些材料成为太阳能研究的前沿。在这里，我们提出了通过飞秒瞬时吸收光谱测量CH(3)NH(3)PbL(1)薄膜的激发态性质的新见解。在760 nm处的光致漂白恢复表明，带边复合遵循二级动力学，表明主要的弛豫途径是自由电子和空穴的复合。此外，钙钛矿薄膜中电荷的积累导致了本征禁带的增加，这符合Burstein-Moss能带填充模型。研究了复合机制和带边移动作为光生载流子浓度的函数，并用来解释杂化钙钛矿中载流子的行为。这些结果提供了对半导体有机金属卤化物钙钛矿的本征光物理的洞察，对光伏和光电子应用具有直接的意义。
The unique and promising properties of semiconducting organometal halide perovskites have brought these materials to the forefront of solar energy research. Here, we present new insights into the excited-state properties of CH(3)NH(3)Pbl(1) thin films through femtosecond transient absorption spectroscopy measurements. The photoinduced bleach recovery at 760 nm reveals that band-edge recombination follows second-order kinetics, indicating that the dominant relaxation pathway is via recombination of free electrons and holes. Additionally, charge accumulation in the perovskite films leads to an increase in the intrinsic bandgap that follows the Burstein-Moss band filling model. Both the recombination mechanism and the band-edge shift are studied as a function of the photogenerated carrier density and serve to elucidate the behaviour of charge carriers in hybrid perovskites. These results offer insights into the intrinsic photophysics of semiconducting organometal halide perovskites with direct implications for photovoltaic and optoelectronic applications.