Evaluation of the influence of hydrogen-dilution ratio and doping on the properties of a-SiGe:H films

The influence of hydrogen-dilution ratio (R) and phosphorus doping on the electrical and structural properties of a-SiGe:H thin films deposited by PECVD at 200 °C is evaluated. The electrical characterization results showed that a-SiGe:H films possess an optimized resistivity due to doping and the set of deposition conditions, which comes from R with an optimal value. From FTIR analysis, it is found that phosphorus doping promotes the formation of Si–H and Ge–H bonds and reduces the weak Si–Si bonds. While the hydrogen dilution ratio is directly related to the incorporation of Ge in the solid phase. Furthermore, the Raman spectroscopy confirms that every analyzed sample possesses an amorphous phase. In conclusion, hydrogen-dilution ratio and phosphorus doping improved the quality of a-SiGe:H alloy films deposited by low-frequency PECVD at low temperatures. Therefore, a-SiGe:H material with improved properties obtained in this work has a potential application in flexible electronics as an inorganic semiconductor and a solar cell as an emitter.