Strain-Modulated Photoelectric Responses from a Flexible α-In2Se3/3R MoS2 Heterojunction

Abstract Semiconducting piezoelectric α-In 2 Se 3 and 3R MoS 2 have attracted tremendous attention due to their unique electronic properties. Artificial van der Waals (vdWs) heterostructures constructed with α-In 2 Se 3 and 3R MoS 2 flakes have shown promising applications in optoelectronics and photocatalysis. Here, we present the first flexible α-In 2 Se 3 /3R MoS 2 vdWs p-n heterojunction devices for photodetection from the visible to near infrared region. These heterojunction devices exhibit an ultrahigh photoresponsivity of 2.9 × 10 3 A W −1 and a substantial specific detectivity of 6.2 × 10 10 Jones under a compressive strain of − 0.26%. The photocurrent can be increased by 64% under a tensile strain of + 0.35%, due to the heterojunction energy band modulation by piezoelectric polarization charges at the heterojunction interface. This work demonstrates a feasible approach to enhancement of α-In 2 Se 3 /3R MoS 2 photoelectric response through an appropriate mechanical stimulus.