Study Of Photoelectric Performance And Microstructure Of Nano-Morphous Silicon Thin Film

The purpose of this work was analyzing the relation between microstructure and photoelectrical performances of the amorphous silicon thin film containing nanoparticles made by hot-wire chemical vapor deposition (HWCVD). I characterized the photovoltaic performance of the Si thin film firstly, and then analyzed the microstructure of the thin film. We characterized photovoltage & photocurrent of the samples by the surface photo voltage spectrum (SPS), measured square resistance by the four defecting needles, examined carrier concentration by the physical property measurement system (PPMS), and detected UV-Vis reflecting spectrums by the UV-Visible spectrophotometer. And then we studied the photoelectric performance and stability by comparing the result now and two years ago. We studied the surface structure by the scan electron microscope (SEM), and section structure and high-resolution image of the Si thin film by the transmission electron microscope (TEM). The crystal status of samples was investigated by micro-Raman scattering spectroscopy. And I calculated the Si thin film crystallization volume proportion, average size, and photoelectrical convert efficiency.The results showed that the photo voltage performance and stability of the Si thin film improved greatly than the Si wafer. The surface structure of the sample we produced was changed, what was good for light trapping. The amorphous embedded nanoparticles structure, the bulk of which was about several nanometers (nm), was observed using high resolution transmission electron microscope (HRTEM). The crystallization of the thin film enhanced and the particles size increase from surface of the thin film to underlay with continuous change. The crystallization volume proportion was about 15.4% with the average size at about 11nm, and photoelectrical convert efficiency was about 17.9%, which was 8.2% higher than the C-Si wafer. The carrier consistency of the thin film was greatly improved due to quantum effect of the nanoparticles contained in the a-Si thin film. And the increasing of the carrier consistency is the main reason of the improvement of the sample. We concluded that reduce deposition rate of the Si thin film properly could improve the microstructure property and the macro photoelectric performance.