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

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.