非晶硅氢薄膜本征层光电二极管的光电流与电子结构分析

Hydrogenated amorphous silicon (a-Si:H) has garnered significant interest due to its fundamental physical properties and potential for cost-effective photodiode applications. In this study, we examine how photocurrent and electronic structure are influenced by hydrogen content in a-Si:H films deposited on indium tin oxide substrates. A combination of Raman Spectroscopy, AFM, HRTEM, XPS, and FESEM was employed to explore the optical characteristics and electronic state density across varying crystallinity levels, from nanoscale crystals to amorphous a-Si:H films. Spectroscopic ellipsometry was utilized to analyze the observed optical and electronic structures. The complex dielectric function aligns well with microscopic calculations related to energy shifts and the broadening of interband transitions due to electron–hole interactions. Notably, we identified a room-temperature photoconductive voltage responsiveness of 3.62 within the linear J–V characteristic, with Jpeak measured at 6.88 A/cm 2 and Jvalley at 1.74 A/cm 2 . In addition, a resonant excitonic effect in a-Si:H was observed, attributed to strong electron–hole and electron–electron interactions beyond the optical band gap. These findings highlight hydrogen’s critical influence in defining excitonic and plasmonic properties in a-Si:H films, making them promising candidates for photodiode applications.