Enhanced Self-Powered Photodetection Performance of p-Si/n-BaTiO3 Film through the Photovoltaic–Pyroelectric Coupled Effect

Abstract

Although the novel photovoltaic effects exhibited by ferroelectric materials have been applied for harnessing solar energy, the wide bandgaps often lead to low power conversion efficiencies, below 0.5%, as they absorb only 8–20% of the solar spectrum. In addition to harvesting solar energy, these ferroelectric materials have shown promise for photodetector applications, particularly for sensing near-UV irradiation. This study presents a novel self-powered broadband photodetector based on BaTiO₃ thin film. The device, fabricated to incorporate the pyroelectric effect into the heterojunction, achieved responsivities and detectivities of 1.35, 0.91, 0.12, and 0.08 mA/W, as well as 2.25 × 10¹⁰, 0.04 × 10¹⁰, 0.003 × 10¹⁰, and 0.002 × 10¹⁰ Jones, respectively, at 365, 456, 532, and 632 nm, respectively, which surpass the performance reported for any other 4-stage pyroelectric-effect-based self-powered BaTiO₃-based photodetector. The device also exhibited high photosensitivities of 7161%, 21900%, 3183%, and 1346% at the corresponding wavelengths at 0 V. By utilizing the light-induced coupled photovoltaic–pyroelectric effect, the photodetector obtained a remarkable enhancement in the responsivity and detectivity of over 2091%, in contrast to the photovoltaic effect. In addition, the photocurrent response caused by the photovoltaic–pyroelectric effect is thoroughly defined, and the impacts of light wavelength, power intensity, and bias voltage are explored. This study presents a promising strategy to increase the photocurrent of ferroelectric-based photodetectors, paving the way for advancements in their adoption in various optoelectronic devices for industrial and innovative applications.