Strong Covalent Coupling in Vertically Layered SnSe<sub>2</sub>/PTAA Heterojunctions Enabled High Performance Inorganic–Organic Hybrid Photodetectors
Yuan‐Hao Zhu, Bohan Feng, Yuhan Su, Guangyuan Li, Yingming Liu, Yuxin Hou, Jie Zhang, Wenjie Li, Guo‐Hua Zhong, Chunlei Yang, Ming Chen
Abstract
Controllable large-scale integration of two-dimensional (2D) materials with organic semiconductors and the realization of strong coupling between them still remain challenging. Herein, we demonstrate a wafer-scale, vertically layered SnSe 2 /PTAA heterojunction array with high light-trapping ability via a low-temperature molecular beam epitaxy method and a facile spin-coating process. Conductive probe atomic force microscopy (CP-AFM) measurements reveal strong rectification and photoresponse behavior in the individual SnSe 2 nanosheet/PTAA heterojunction. Theoretical analysis demonstrates that vertically layered SnSe 2 /PTAA heterojunctions exhibit stronger C–Se covalent coupling than that of the conventional tiled type, which could facilitate more efficient charge transfer. Benefiting from these advantages, the SnSe 2 /PTAA heterojunction photodetectors with an optimized PTAA concentration show high performance, including a responsivity of 41.02 A/W, an external quantum efficiency of 1.31 × 10 4 %, and high uniformity. The proposed approach for constructing large-scale 2D inorganic–organic heterostructures represents an effective route to fabricate high-performance broadband photodetectors for integrated optoelectronic systems.