Work Function Determination of Transparent Contact for a:Si/c-Si Heterojunction Solar Cells

It has been largely demonstrated that the a-Si/c-Si heterojunction solar cells can reach high efficiency. A central role in this type of structure is played from the transparent contact work function, whose value affects strongly the heterojunction's band structure at the interface with the other layers of the cell. In the present work, different materials have been fabricated in order to test and optimize their application as transparent contacts in our heterojunction solar cells. The work function mapping through Scanning Kelvin Probe technique has been used to characterize the electronic surface morphology and homogeneity of the realized layers and to determine the mean work function values over the scanned areas.