Boosting tribo-photovoltaic effect in perovskite triboelectric nanogenerators by regulating built-in potential through p-n junctions

Abstract

CsPbBr₃ perovskite has become a star material for triboelectric nanogenerators (TENGs) due to its excellent optoelectronic properties, dielectric properties and stability in the atmosphere. However, regulating its optoelectronic and dielectric properties through charge-directed transport and separation within TENGs has not been comprehensively explored. Herein, p-n junction is constructed to form built-in potential (E_built-in) for charge-directed transport by introducing a semiconductor layer beneath the perovskite film in perovskite-TENGs, where the effect of E_built-in’s direction and intensity on output performance is systematically investigated. Introducing the p-type semiconductor NiO_x creates a reversed E_built-in, which enhances the surface triboelectric charge density of the perovskite and achieves improved triboelectric output performance of 205 V and 43 μA cm⁻² for the PVDF-CsPbBr₃ TENG. Conversely, the n-type semiconductor SnO₂ establishes a parallel E_built-in, greatly facilitating the extraction and separation of photogenerated carriers, leading to a high current density of 1.4 mA cm⁻² under illumination based on the triboelectric-photoelectric coupling effect. Moreover, the CsPbBr₃-TENGs demonstrate superior stability and a broad linear response range and fast photoresponsivity, proving their potential for practical applications in various self-powered optoelectronic detection devices.