Self-Powered CsPbBr₃ Perovskite Nanonet Photodetector with a Hollow Vertical Structure

For most commercial photodetectors (PDs), incident light is illuminated from the top or side of the device, but the opaque electrode (gold, copper, or aluminum, etc.) on the top will block part of the light from entering, wasting the efficiency of light utilization. Herein, to solve this issue, we introduced perovskite nanonet PDs with a hollow vertical structure by using a polystyrene microsphere template. Compared with ordinary thin film devices, our reticulated hollow vertical structure devices not only can enable easy entrance of the light from the reticulated hollow surface of the devices but also can reduce the reflection of light, resulting in better device performance. For our optimal CsPbBr₃ perovskite PDs, high photoelectric performances were achieved with the switching ratio up to 4.17 × 10⁴, a detectivity of 7.44 × 10¹¹ Jones, a linear dynamic range of 108 dB, and the rise/fall time of 0.1/0.16 ms. More importantly, because of the reticulated hollow structure, our device performance showed less reduction when the incident light was illuminated from the top than from the bottom. These results may be of great reference value for improving the photoelectric performance of silicon-based devices or deep ultraviolet PDs.