A sensitive self-powered perovskite photodetector via noise suppression with poly(vinylidene fluoride–trifluoroethylene) doping for defect passivation

Abstract

The rapid advancement of self-powered perovskite photodetectors (PDs) in recent years has been hindered by numerous defects present in solution-processed perovskite polycrystalline films, significantly impacting device performance. Of particular concern is the influence of these defects on device noise, a critical parameter directly affecting detector sensitivity. This study proposes the incorporation of poly(vinylidene fluoride–trifluoroethylene) (PVT) additives into FA_0.9MA_0.05Cs_0.05PbI₃ perovskite precursor solutions to alleviate defect formation and enhance detector sensitivity. By optimizing the PVT concentration to 0.05 mg L⁻¹, the photodetector (PD) demonstrates remarkable improvement, achieving a low noise power spectral density (0.1 pA Hz^−1/2) and dark current density (2.12 nA cm⁻²) at zero bias. The device exhibits a notable decrease in defect density by an order of magnitude through the concurrent passivation of shallow-level defects with PVT. Additionally, the PD shows a high specific detection rate (D* = 2.8 × 10¹³ jones) at 700 nm, accompanied by a linear dynamic range exceeding 101 dB. This research not only advances our understanding of noise suppression mechanisms but also unveils the potential application of high-sensitivity PDs for real-time heart rate monitoring, showing promise for significant advancements in human health monitoring technology.