We discuss the transport properties of CsPbBrxI3−x perovskite nanocrystal arrays as a model ensemble system of caesium lead halide-based perovskite nanocrystal arrays. While this material is very promising for the design of light emitting diodes, laser, and solar cells, very little work has been devoted to the basic understanding of their (photo)conductive properties in an ensemble system. By combining DC and time-resolved photocurrent measurements, we demonstrate fast photodetection with time response below 2 ns. The photocurrent generation in perovskite nanocrystal-based arrays is limited by fast bimolecular recombination of the material, which limits the lifetime of the photogenerated electron-hole pairs. We propose to use nanotrench electrodes as a strategy to ensure that the device size fits within the obtained diffusion length of the material in order to boost the transport efficiency and thus observe an enhancement of the photoresponse by a factor of 1000.

中文翻译：

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克服 CsPbX3 纳米晶体阵列中复合限制光电流产生的策略

我们讨论了 CsPbBrxI3−x 钙钛矿纳米晶体阵列的传输特性，作为基于铯铅卤化物的钙钛矿纳米晶体阵列的模型集成系统。虽然这种材料在设计发光二极管、激光器和太阳能电池方面非常有前途，但很少有工作致力于对它们在集成系统中的（光）导电特性的基本了解。通过结合直流和时间分辨光电流测量，我们展示了时间响应低于 2 ns 的快速光电检测。基于钙钛矿纳米晶体的阵列中的光电流产生受到材料快速双分子复合的限制，这限制了光生电子-空穴对的寿命。