Broadband photodetection in WSe₂ and Er doped ZnO(EZO) heterostructure

This letter reports Al/EZO/WSe ₂ / PEDOT:PSS/ITO structure based broadband photodetector using low-cost solution method. The p-type WSe ₂ layer forms a heterojunction with n-type Erbium doped ZnO(EZO) layer. PEDOT:PSS layer works as a hole transport layer deposited over ITO coated PET substrate. The proposed device displays a high External Quantum Efficiency (EQEs)/Responsivity R_s (A/W) of 500%/1.60, 2.05 ×10 ⁴ %/91.20, 8.1×10 ³ % / 68.50 at 400nm (UV), 550nm (Visible) and 1050nm (NIR) respectively, under-1.5Vbias.