Piezo‐Phototronic Effect in 2D α‐In2Se3/WSe2 van der Waals Heterostructure for Photodetector with Enhanced Photoresponse. Issue 20 (16th July 2021) - Zhao, Yuqian
Abstract: 2D materials offer a platform that allows the creation of flexible functional devices with various properties due to their extraordinary properties. In this work, the influence of piezo‐phototronic effect on a flexible α‐In2 Se3 /WSe2 van der Waals (vdW) heterostructure is investigated and the strain‐regulated photoresponse of the device is examined. Owing to the noncentrosymmetric structure of III–VI compound α‐In2 Se3, the strain‐induced piezo‐potential modulates the band slope near the P‐N junction interface, improving the transfer characteristics and separation efficiency of photogenerated electron–hole pairs by piezo‐phototronic effect. With applying the tensile strain of 0.433%, the photocurrent of the photodetector can be enhanced by about 18 times. Furthermore, the photodetectors present remarkable photoresponsivity and detectivity that can reach up to 4.61 × 10 5 A W −1 and 4.34 × 10 14 Jones, respectively. These results indicate that the piezo‐phototronic effect can be introduced to facilitate strain‐modulated vdW P‐N heterojunction photodetector, which provides an insightful design of 2D material‐based vdW heterostructure toward high‐performance flexible optoelectronics. Abstract : Flexible α‐In2 Se3 /WSe2 van der Waals P‐N heterojunction photodetectors are demonstrated with an enhanced performance by the piezo‐phototronic effect. The photocurrent under 0.433% strain achieves over 18 times improvement in comparison to strain‐free condition. These extraordinary results open up an insightful design of 2D material‐based vdW heterostructure toward high‐performance flexible optoelectronics.