Photo detector based on graded band gap perovskite crystal

摘要

In this work, millimeter sized graded band gap mixed halide hybrid perovskite crystal have been synthesized by utilizing reversible halide exchange property of hybrid perovskites. Optoelectronic performance of photo diodes fabricated using the graded band gap crystal has been studied in details. Band gap engineering has formed a smoother path for carrier transport by aligning HOMO and LUMO levels with the charge collection layers. This is reflected in good diode quality and fast photo response has been achieved. On the other hand, effect from both bulk and surface recombination of photo generated carriers are observed in the plateau type spectral response curve with a peak near band edge.