PEDOT:PSS/Yb-Doped ZnO Heterojunction Based Flexible UV Photodetector

This letter proposes an organic-inorganic heterojunction structure based flexible Ultraviolet (UV) photodetector. The proposed structure consists of Al/PEDOT:PSS/ Yb doped ZnO (YZO)/Al structure fabricated by the low-cost spin coating method over a flexible PET substrate. At −2V voltage bias and 357 nm operating wavelength, the proposed structure gives the maximum responsivity of 0.33 A/W, sensitivity of 33.07, detectivity of 1.01
$\times \,\,{10}^{14}$
Jones, and external quantum efficiency of 113% (at
$0.257~\mu \text{W}$
optical excitation). Further, the rise time of 70 ms and the fall time of 30 ms are obtained at 357 nm. The proposed photodetector thus shows an excellent performance in the UV region.