Silicon-Germanium Thin Films Prepared by RF-PECVD and Its Optical Properties

The structural characteristics, deposition rate, absorption spectra and optical band gap of the silicon-germanium thin films, which were prepared by RF-PECVD, had been researched under the diffferent Germane´s concentration. By test of Raman, all the silicon-germanium thin films presented amorphous and the spectral peaks were located around 480cm-1. According to the trend of optical band gap, the band gap of film could be adjusted effectively by increasing the concentration of Germane in the reactive gases. Also, the absorption in the long-wave region and the response to the solar spectrum were able to be improved and expanded.