为改善有机-无机铅卤钙钛矿的空气稳定性, 采用高温热注入法合成了两种不同尺寸的全无机钙钛矿CsPbBr3纳米晶。由于晶粒尺寸对纳米晶薄膜电学性能具有决定性的作用, 研究了CsPbBr3纳米晶尺寸对薄膜光电导探测器光电响应性能的影响。结果表明: 纳米片薄膜的光电流是纳米立方块薄膜的100倍, 归结于二维CsPbBr3纳米片薄膜更少的晶界导致了更长的载流子扩散长度。对性能更加优异的纳米片薄膜光电探测器进行了全面的性能评价, 低的噪声等效功率和高的归一化探测率表明其具有优异的弱光探测能力。

In order to improve the air-stability of organic-inorganic lead halide perovskite, two kinds of all-inorganic perovskite CsPbBr3 nanocrystals with different sizes were synthesized by high temperature hot-injection method. Because the nanocrystal size plays a key role in determining electrical performance of nanocrystal film, the effect of CsPbBr3 nanocrystal size on the photoelectric response of thin film photoconductive photodetector was studied. The results show that the photocurrent of nanosheet film is 100 times higher than that of nanocube film, resulting from the large carrier diffusion length of 2D CsPbBr3 nanosheet film with less boundary. Finally, an overall performance evaluation on nanosheet film photodetector with higher photoreponse was conducted, and low noise equivalent power and high specific detectivity demonstrate its good weak light detection capability.