Liquid-Phase Epitaxial Growth of Perovskite Crystals on Amorphous IGZO Films for High-Performance Heterostructure Photodetectors

During the past decade, hybrid inorganic–organic perovskites (HIOPs) and amorphous metal-oxide semiconductors (AMOSs) have attracted enormous interest in the construction of optoelectronic and electronic devices, respectively. Herein, a liquid-phase epitaxy method is introduced for the first time to construct phenylethylamine lead iodide (PEAPbI) crystals on an indium gallium zinc oxide (IGZO) film, which is obtained by the sol–gel method. The fundamental material and structural properties are performed. Compared with a pristine layer, a bilayer of the PEAPbI/IGZO absorber shows improved absorption capability in the spectrum from ultraviolet to visible. A heterojunction photodetector (HJPD) is constructed and compared with the PEAPbI crystal device. Under the incident light of 365 and 405 nm, the photo-to-dark current ratio (PDCR) and responsivities (R) of the HJPD are about 10 times higher than those of the latter, and the detectivities (D*) increase by 2 orders of magnitude as well. The device’s working mechanism for the HJPD is then discussed. Based on the type-II energy band structure, it is found that the photogenerated carriers can be separated more efficiently in the heterostructure device and realize the enhancement of the device’s photoresponse properties. This work provides a novel approach to building heterostructures for large-area, low-cost, and high-performance optoelectronic devices.