Enhanced Performances of PVK/ZnO Nanorods/Graphene Heterostructure UV Photodetector via Piezo‐Phototronic Interface Engineering

Abstract

AbstractThe piezo‐phototronic effect can effectively engineer the energy band structure at the local interface of piezo‐semiconductor junction, and thus improve the performance of optoelectronics. In this work, a high‐performance poly(9‐vinylcarbazole) (PVK)/ZnO nanorods/graphene heterostructure photodetector is designed and fabricated using a multi‐step process. By introducing a −1.093% compressive strain to the hybrid heterostructure, carrier‐dynamics modulation at the local junctions can be induced by the piezoelectric polarization, and the photoresponsivity and the specific detectivity of the photodetector can be enhanced ≈440% and ≈132% under UV light illumination with the peak values up to 80.6 A W−1 and 2.3 × 1011 Jones, respectively. The photoresponse enhancement is attributed to the piezopotential generated at PVK/ZnO and ZnO/graphene interfaces, which promote the separation and transfer of photogenerated carriers. Physical working mechanism behind the observed results is discussed via energy band diagram. This work not only presents a new way to achieve the higher performance in photodetectors by fully utilizing piezo‐phototronic interface engineering but also provides a deep understanding of piezo‐phototronic effect on optoelectronic devices.