A general strategy for enhancing the performance of Ga2O3-based self-powered solar-blind photodetectors through band structure engineering

The spectral response of Ga(2)O(3 )almost perfectly covers the 200-280 nm solar-blind ultravioletwavelength range, making it an ideal semiconductor material for fabricating solar-blindultraviolet photodetectors. However, due to the considerably deep valence band energy of Ga2O3 the construction of heterojunctions typically induces a significant valence band offset(triangle Ev). Herein, we present a band engineering approach to improve the performance of Ga(2)O(3 )bases photodetectors. This pronounced valence band barrier can strongly influence the transportof photo-generated charge carriers, especially the extraction of holes in the depletion region. Byintroducing nitrogen (N) during the growth process, we elevated the valence band of Ga(2)O(3 )by0.43 eV. The organic high-molecular-weight material of PEDOT:PSS has been utilized inconjunction with Ga(2)O(3 )to construct heterojunction photodetectors. The photodetectors exhibitexcellent self-powered characteristics, with responsivity, detectivity, and response time beingnearly ten times higher than those of Ga(2)O(3 )photodetectors before band structure modulation.The investigation into modulating the band structure of Ga2O3 carried out in this study will laythe theoretical foundation and provide technical solutions for developing satisfactoryself-powered photodetectors.