FAPbI3有机无机杂化钙钛矿光电探测器还存在一些问题, 合成纯α相光敏钙钛矿需要较高的退火温度(150~160 ℃), 不利于柔性器件的制备; 另外, 在常温下, FAPbI3容易发生α→δ的相变, 器件的空气稳定性很差。本文制备了Cs掺杂的二极管型FA1-xCsxPbI3光电探测器。结果表明, Cs的掺杂一方面有效降低了合成纯α 相FA钙钛矿的退火温度, 另一方面提高了器件性能以及空气稳定性。对比不同Cs掺杂浓度的器件性能, 发现掺杂摩尔分数为10%时, 器件性能最优, 其开关比可达1.6×105, 响应速度达到7.1 μs, 在350~800 nm宽光谱范围内探测率都在1012 cm·Hz1/2·W-1(Jones)量级。本研究为实现低温制备高性能高稳定性的FA钙钛矿光电探测器提供了一条可行的途径。

For NH2CHNH2PbI3 (FAPbI3) photodetectors, the challenges are that the high annealing temperature (150-160 ℃) for pure α-FAPbI3 perovskite are not suitable for flexible substrates and the transition from α to δ phase makes the photodetectors unstable in air at room temperature. In this paper, we synthesized pure α-phase FA1-xCsxPbI3 perovskite by doping Cs at an annealing temperature of 100 ℃ and fabricated FA1-xCsxPbI3 photodetectors. The devices exhibit best performance and air stability. At -0.5 V, a high on/off current ratio of 1.6×105 and fast response times of 7.1 μs are obtained, and the specific detectivities are above 1012 cm·Hz1/2·W-1(Jones) over a broad spectral range from 350-800 nm.