Effects of process parameters on μc - Si _{1 − X}Ge _X:H solar cells performance and material properties

Abstract

On our way to develop a very thin and highly efficient triple-junction thin-film solar cell in a-Si:H/ μ c-Si:H/ μ c-SiGe:H configuration and μ c-SiGe:H single cell samples were prepared and characterized using an industrial relevant 13.56 MHz 0.5 nm/s process on an industrial like 30 × 30 cm ² PECVD tool. To attain a better understanding of the μ c-SiGe:H absorber we varied process pressure, germane flow, dilution and silane flow while looking at the electrical and material properties. By realizing a total absorber thickness less than 2 μ m for high efficiency cell concepts in triple technology, our intention is to develop an industrial relevant process with attractive fabrication times by benefiting from the enhanced absorption of μ c-SiGe:H compared to μ c-Si:H.