Toward Smart, Flexible, and Omnidirectional Self-Powered Photodetection by an All-Solution-Processed In 2 O 3 /Pbl 2 Heterojunction.

Amorphous In 2 O 3 film is emerging as a promising oxide semiconductor for next-generation electronics and optoelectronics owing to high mobility and wide band gap. However, the persistent photocurrent phenomenon and high carrier concentration in amorphous In 2 O 3 film are challenging the photodetection performances, resulting in a long response time and low I light / I dark ratio. In this work, the In 2 O 3 /PbI 2 heterojunction is constructed by an all-solution synthesis process to inhibit the persistent photocurrent phenomenon and large dark current. Benefiting from the built-in electric field at the heterojunction interface, the In 2 O 3 /PbI 2 heterojunction photodetector exhibits excellent self-powered photodetection performances with an ultralow dark current of 10 -12 A, a high I light / I dark ratio of 10 4 , and fast response times of 0.6/0.6 ms. Furthermore, the entire solution synthesis process and amorphous characteristics enable the fabrication of an In 2 O 3 /PbI 2 heterojunction photodetector on arbitrary substrates to realize specific functions. When configured onto the polyimide substrate, the In 2 O 3 /PbI 2 heterojunction photodetector shows excellent mechanical flexibility, bending endurance, and photoresponse stability. When implanted onto the transparent substrate, the In 2 O 3 /PbI 2 heterojunction photodetector exhibits an outstanding omnidirectional self-powdered photodetection performance and imaging capability. All results pave the way for an all-solution-processed amorphous In 2 O 3 film in advanced high-performance photodetectors.