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

Semiconducting piezoelectric alpha-In2Se3 and 3R MoS2 have attracted tremendous attention due to their unique electronic properties. Artificial van der Waals (vdWs) heterostructures constructed with alpha-In2Se3 and 3R MoS2 flakes have shown promising applications in optoelectronics and photocatalysis. Here, we present the first flexible alpha-In2Se3/3R MoS2 vdWs p-n heterojunction devices for photodetection from the visible to near infrared region. These heterojunction devices exhibit an ultrahigh photoresponsivity of 2.9 x10(3) A W-1 and a substantial specific detectivity of 6.2x 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 alpha-In2Se3/3R MoS2 photoelectric response through an appropriate mechanical stimulus.

Automated summary

Semiconducting piezoelectric alpha-In2Se3 and 3R MoS2 have unique electronic properties, and their heterostructures show promising applications in optoelectronics and photocatalysis. The flexible alpha-In2Se3/3R MoS2 vdWs p-n heterojunction devices exhibit high photoresponsivity and specific detectivity, with photocurrent enhancement under different strain conditions, demonstrating a feasible approach to enhance photoelectric response through mechanical stimulus.