Perovskite Grown in Gallium Nitride Nanowire Matrix for Stable and High-Efficiency X-Ray Detection

High-quality quasi-2D perovskites in a GaN nano-wire matrix are grown to build a 3D hetero-structure for high-performance X-ray sensing. In the 3D hetero-structure, GaN nano-wire matrix serves as an n-type charge collector that can rapidly extract carriers through the bulk film of the perovskite layer. Together with a p-type top electrode, a p-i-n diode with the 3D hetero-structure is built, that exhibits a rectified current-voltage characteristic. After analyzing the interface energy alignment, it is found that the fermi levels of the perovskite and GaN are aligned in the dark, and a quasi-fermi level splits upon illumination, introducing a built-in electrical field at the interface. As a result, strong photo-induced current is observed from the diode without an external field. Finally, the 3D diode for X-ray detection demonstration is used, revealing a sensitivity of 308.9 mu C Gyair-1 cm-2 at an exceptionally low applied field of 0.125 V mu m-1. The X-ray-induced signal from the 3D diode is stable after 155 cycles of X-ray irradiation under a constant electric field. This demonstration informs a new 3D architecture for high-performance X-ray sensing, and it shows that GaN is a robust n-type interface for perovskite optoelectronic devices. A 3D hetero-junction photodiode with quasi-2D perovskite grown in GaN nanowire matrix is built for high-performance X-ray sensing. GaN nanowire serves as a robust n-type charge collection layer with proper band alignments that rapidly extracts electrons ionized through the bulk volume of perovskite. This work suggests a robust n-type interface for perovskite devices. image