论文标题
卤化物钙钛矿纳米板片中激子 - 外激体歼灭的厚度依赖性
Thickness-Dependence of Exciton-Exciton Annihilation in Halide Perovskite Nanoplatelets
论文作者
论文摘要
激子 - 外激体歼灭（EEA）和螺旋钻重组是在高载体密度下的半导体光电设备中发生的有害过程。尽管构成了在半导体纳米晶体（NCS）中实现激光的主要障碍之一，但对NC大小的依赖性尚未完全理解，尤其是对于那些较弱且强限制的尺寸的依赖性。在这里，我们使用差分传输光谱来研究EEA对厚度控制的2D卤化物钙钛矿纳米片（NPLS）的物理尺寸的依赖性。我们发现EEA寿命在7-60 PS的顺序上非常短。此外，根据τ_2〜D^5.3的幂律依赖性，它们由NPL厚度强烈确定。其他测量结果表明，EEA寿命也增加了具有较大横向尺寸的NPL。这些结果表明，对物理维度的精确控制对于破译该过程的基本定律至关重要，尤其是在1D和2D NC中。
Exciton-exciton annihilation (EEA) and Auger recombination are detrimental processes occurring in semiconductor optoelectronic devices at high carrier densities. Despite constituting one of the main obstacles for realizing lasing in semiconductor nanocrystals (NCs), the dependencies on NC size are not fully understood, especially for those with both weakly and strongly confined dimensions. Here, we use differential transmission spectroscopy to investigate the dependence of EEA on the physical dimensions of thickness-controlled 2D halide perovskite nanoplatelets (NPls). We find the EEA lifetimes to be extremely short on the order of 7-60 ps. Moreover, they are strongly determined by the NPl thickness with a power-law dependence according to τ_2~d^5.3. Additional measurements show that the EEA lifetimes also increase for NPls with larger lateral dimensions. These results show that a precise control of the physical dimensions is critical for deciphering the fundamental laws governing the process especially in 1D and 2D NCs.
