Perovskite solar cells have developed rapidly in recent years as the third generation solar cells. In spite of the great improvement achieved, there still exist some issues such as undesired hysteresis and indispensable high temperature process. In this work, bulk heterojunction perovskite-phenyl-C 61 -butyric acid methyl ester solar cells have been prepared to diminish hysteresis using a facile two step spin-coating method. Furthermore, high quality tin oxide films are fabricated using pulse laser deposition technique at room temperature without any annealing procedure. The as fabricated tin oxide film is successfully applied in bulk heterojunction perovskite solar cells as a hole blocking layer. Bulk heterojunction devices based on room temperature tin oxide exhibit almost hysteresis-free characteristics with power conversion efficiency of 17.29% and 14.0% on rigid and flexible substrates , respectively.
All-inorganic photodetectors based on scattered CsPbBr 3 nanoplatelets with lateral dimension as large as 10 µm are fabricated, and the CsPbBr 3 nanoplatelets are solution processed governed by a newly developed ion-exchange soldering mechanism. Under illumination of a 442 nm laser, the photoresponsivity of photodetectors based on these scattered CsPbBr 3 nanoplatelets is as high as 34 A W −1 , which is the largest value reported from all-inorganic perovskite photodetectors with an external driven voltage as small as 1.5 V. Moreover, the rise and fall times are 0.6 and 0.9 ms, respectively, which are comparable to most of the state-of-the-art all-inorganic perovskite-based photodetectors. All the material synthesis and device characterization are conducted at room temperature in ambient air. This work demonstrates that the solution-processed large CsPbBr 3 nanoplatelets are attractive candidates to be applied in low-voltage, low-cost, ultra highly integrated optoelectronic devices.