Self-Powered Photodetectors Based on Ruddlesden-Popper 2D Hybrid Perovskites with Carbazole Derivatives

Recently, carbazole-based organic cations have attracted the interests of scientists in a variety of fields for their potential application in 2D layered hybrid perovskite solar cells. These materials have demonstrated enhanced stability compared to other 2D and 3D hybrid perovskites<br/>which could allow them to achieve the level of self-sufficiency and environmental durability required of commercial solar cells. However, the potential incorporation of these highly efficient materials in photodetection has been largely unexplored. In this study, we synthesized CzEAP, a 2D layered organic-inorganic hybrid perovskite (OIHP) containing PbI₂ and a large organic ammonium 1-(9H-carbazol-9-yl) ethanaminium iodide (CzEAI) in a 1:2 molar ratio. We developed a series of thin films and devices in the configuration ITO/PEDOT:PSS/(CzEA)₂PbI₄/PCBM/BCP/Al using this novel OIHP. We conducted atomic force microscopy, UV Vis, photoluminescence, and external quantum efficiency measurements on these films and devices to assess their surface and optical properties. We also determined the hole mobility of CzEAP-based hole only devices in the configuration ITO/PEDOT:PSS/(CzEA)₂PbI₄/MOO₃/Ag. Through optimization of the deposition procedure for this perovskite, we constructed novel photodetector devices with a specific detectivity of 6.95 × 10¹⁰ Jones at 485 nm illumination and the ability to operate in a self-powered condition at 0V. The development of highly efficient self-sustaining photodetectors is essential to the progression of a wide range of fields including optical communications, security, video imaging, biomedical imaging, motion detection, and gas sensing.