Responsivity Spectrum Tailoring of Pentacene:ZnO Multi-Nano Film-Based Bulk Heterojunction Photodetector

A Al/Al
₂
O
₃
/Pentacene:ZnO/ PEDOT:PSS/ITO photodetector structure is proposed and analyzed. The pentacene:ZnO blend film used as an active layer of the device is studied briefly for its structural and optical properties. The proposed photodetector is shown to be tailored for operation in UV and visible region by changing pentacene:ZnO (P:Z) blend film ratio as 1:1, 1:2 and 2:1. For the proposed photodetector optimum performance in the UV region is obtained for P:Z ratio of 1:2. The obtained responsivity is 9.26 A/W, detectivity is 1.74 × 10
¹³
Jones and external quantum efficiency (EQE) is 3.9 × 10
³
%, at wavelength 302 nm. Further, for the visible region, responsivity is 0.71 A/W, detectivity is 0.15 × 10
¹³
Jones and external quantum efficiency (EQE) is 140%, at wavelength 628 nm for P:Z ratio of 2:1. Thus, responsivity tailoring by changing the blend ratio of the active layer facilitates the route for the fabrication of suitable optoelectronic devices for a wide variety of applications.