High Selectivity and Wide Range UV Photodetection in PEDOT:PSS/ Lu $_{\text{0}.\text{27}}$ Sn $_{\text{0}.\text{73}}$ O/ZnO Heterojunction

Ultraviolet (UV) photodetectors have received widespread attention in fields, such as corona inspection, flame detection, and UV communication. In this work, a high-performance PEDOT:PSS/Lu $_{\text{0}.\text{27}}$ Sn $_{\text{0}.\text{73}}$ O/ZnO UV detector prepared on Lu $_{\text{0}.\text{27}}$ Sn $_{\text{0}.\text{73}}$ O films (bandgap $\sim$ 4.9 eV) is obtained through alloy engineering. At 0-V bias, the device is sensitive to a wide range UV (230–400 nm, which covers the UVA, UVB, and UVC bands) illumination and exhibits a rapid response of $\sim$ 90.7 ms. As compared with the performance of Au/Lu $_{\text{0}.\text{27}}$ Sn $_{\text{0}.\text{73}}$ O/ZnO device, a quicker response, higher sensitivity to UVC, and wider range UV photoresponse are equipped in this device. This confirms the key role of the heterojunction constructed by PEDOT:PSS and Lu $_{\text{0}.\text{27}}$ Sn $_{\text{0}.\text{73}}$ O film plays in the excellent performance of this device under 0-V bias.