Self-Powered Multicolor Broadband Photodetector Based on GaSe/WSe₂//WSe₂/BP Van Der Waals Heterostructure

Nowadays, broadband photodetectors are gaining popularity among optoelectronic applications. However, 2-D materials-based Van der Waals heterostructures (vdWHs) photodetectors have a narrow photodetection scope. To broaden the detection bandwidth, a photodetector based on GaSe/WSe
₂
and WSe
₂
/BP parallel-mode heterojunctions is presented in this work. For convenience, the parallel-mode structure of the GaSe/WSe
₂
and WSe
₂
/BP heterojunctions are denoted as “GaSe/WSe
₂
//WSe
₂
/BP.” GaSe/WSe
₂
and WSe
₂
/BP heterojunctions show high detection performances in the ultraviolet-visible (UV-Vis) and visible-near infrared (Vis-NIR) spectra, respectively. Using the photoresponse complementary characteristics of GaSe/WSe
₂
and WSe
₂
/BP heterojunctions, the GaSe/WSe
₂
//WSe
₂
/BP heterojunction photodetector demonstrates self-powered multicolor broadband photodetection cover UV-Vis-NIR spectra. Besides, the photodetector has an on-/off-ratio of ≈ 10
⁴
, ≈ 0.1 pA dark current, and a short response time ( ~ 40 μs). Our work paves the way for developing 2-D materials-based high-performance broadband photodetectors.