Abstract
A hybrid nanostructure with self-assembled 0-D Bi2S3 nanoparticles on 1-D a-Si:H nanowires was developed as a new absorption material in this work. It has been demonstrated the feasibility of using a metal-induced chemical etching process, which is simple, rapid, low-temperature and suitable for large-area production, to fabricate a-Si:H nanowires. The Bi2S3 NPs were self-assembled on the a-Si:H NWs as well as c-Si NWs to test the feasibility for photovoltaic applications. The UV-Vis results showed that the absorption of a-Si:H nanowires was greatly enhanced attributed to superior antireflection properties over a large range of wavelengths. Bi2S3 NPs were successfully synthesized on the surface of as-prepared a-Si:H nanowires and characterized, showing that it could serve as an efficient light harvesting agent. The combination of Bi2S3 NPs and a-Si:H NWs as well as Bi2S3 NPs and c-Si NWs provided the possibility to realize the desired wide-band spectrum of sunlight absorption. As this hybrid system was applied to a-Si:H and c-Si, the superior antireflection properties of NWs along with the integration of Bi2S3 NPs as light harvesting agents yielded a substantial enhancement in the optical absorption. For the solar cell based on Bi2S3 NPs / c-Si NWs, the result showed substantial enhancement in the short-circuit current density and power conversion efficiency compared to that of the solar cell based on only c-Si NWs (Jsc = 1.163 mA/cm2, PCE = 0.044 % for c-Si NWs and Jsc = 9.196 mA/cm2, PCE = 0.802 % for Bi2S3-NPs / c-Si NWs). Thus, the hybrid nanostructures presented in this study provided the feasibility for their future photovoltaic applications.