Boosting lateral photosensing performances in a P(VDF-TrFE)/Bi2Se3/Si heterojunction induced by surface modification and ferroelectric and pyroelectric effects

Abstract

Bi₂Se₃ exhibits not only high carrier mobility but also exceptional thermal stability and robustness, making it an ideal material for ultrafast detection and switching applications in extreme environments. In this work, a high-sensitivity self-powered position-sensitive detector (PSD) is developed using a Bi₂Se₃/Si heterojunction and a P(VDF-TrFE) surface dual-functional layer. The Bi₂Se₃/Si heterojunction displays a wide spectral range of 360–1064 nm, and is capable of providing a remarkable position sensitivity of up to 151.6 mV mm⁻¹ with nonlinearity being kept under 4%. Through the addition of the P(VDF-TrFE) modification layer, the surface electrical conductivity of Bi₂Se₃ is lowered, leading to an enhanced position sensitivity of 333.33 mV mm⁻¹. Moreover, the ferroelectric and pyroelectric properties of P(VDF-TrFE) enable the effective separation and transport of photo-generated carriers, resulting in further improved position sensitivity as high as 710 mV mm⁻¹, with an impressive 368.3% increase. In addition, the PSD also demonstrates an ultrafast response time, with values as low as 35/50 μs. The exceptional performance of the PSD can be attributed to the dually optimized longitudinal and transverse photoelectric processes of the lateral photovoltaic effect induced by the P(VDF-TrFE). These findings carry significant implications for the development of high-performance photosensing devices using novel materials and ferroelectrics.