Ultrasensitive Photodetectors Based on Island-Structured CH3NH3PbI3 Thin Films

CH3NH3PbI3 perovskite-based optoelectronics have attracted intense research interests recently because of their easy - fabrication process and high power conversion efficiency. Herein, we report a novel photodetector based on unique CH3NH3PbI3 perovskite films with island-structured morphology. The light-induced electronic properties of the photodetectors were investigated and compared to those devices based on conventional compact CH3NH3PbI3 films. The island-structured CH3NH3PbI3 photodetectors exhibited a rapid response speed (<50 ms), good stability at a temperature of up to 100 degrees C, a large photocurrent to dark current ratio (I-light/I-dark > 1 X 10(4) under an incident light of similar to 6.59 mW/cm(2), and I-light/I-dark > 1 X 10(2) under low incident light similar to 0.018 mW/cm(2)), and excellent reproducibility. Especially, the performance of the island-structured devices markedly exceed that of the conventional compact CH3NH3PbI3 thin-film devices. These excellent performances render the island-structured device to be potentially applicable for a wide range of optoelectronics.