Microfluidic-Assisted Growth of Perovskite Single Crystals for Photodetectors

The organometal halide perovskites (OMHP) are promising candidates for fast, sensitive, and large area photodetectors. In the last decade, several techniques have been developed with complementary advantages. Film devices are thin and can be scaled to large area, but have a large number of grain-boundaries related defects. Single bulk crystals instead have higher purity, but are thicker and can not be easily produced on large areas. In this work, a microfluidics-assisted technique to realize a controlled growth of OMHP single crystals, in the form of microwires, directly on a conductive patterned substrates, is presented. This technique enables the realization of vertical devices with a pixelated sensor layer. The resulting devices present gain, a responsivity up to 200 AW(-1) and a fast rise time down to 35 mu s. This is the first demonstration of a OMHP vertical device realized on a patterned substrate using microfluidics-assisted techniques.