Interfacial Dedoping Engineering of PEDOT:PSS for High‐Performance Sn–Pb Perovskite NIR Photodetectors

Abstract Tin–lead (Sn–Pb) perovskites are highly promising materials for near‐infrared (NIR) photodetectors (PPDs) due to their broad light absorption and excellent NIR responsivity. However, the high doping level of PEDOT:PSS as the hole transport layer (HTL) can cause interfacial recombination, limiting device performance. In this study, a simple and efficient dedoping strategy is introduced using 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) to enhance the properties of PEDOT:PSS, significantly boosting the performance of Sn–Pb‐based photodetectors. Comprehensive evaluations, including UV–Visible–NIR absorption spectroscopy, Raman spectroscopy, electrical property analysis, and surface potential measurements, are carried out to refine the dedoping process. This treatment improves interfacial passivation, reduces nonradiative recombination, and promotes superior perovskite crystallinity. As a result, devices with dedoped PEDOT demonstrates a considerable reduction in dark current density, a detectivity as high as 10 ¹⁴ Jones measures in the wavelength range of 380 to 960 nm, and a broad near dynamic range (LDR) of 84.5 dB. This simple and efficient dedoping method not only improves device performance but also offers a promising route for advancing high‐performance NIR photodetectors.