Operation of BaSi2 homojunction solar cells on p+-Si(111) substrates and the effect of structure parameters on their performance

Abstract

Operation of n+-BaSi2/p-BaSi2(500 nm)/p+-BaSi2 homojunction solar cells on p+-Si(111) is demonstrated, showing a saturation current density of 9.4 mA cm-2 and an open-circuit voltage of 0.11 V under AM1.5 illumination. Photogenerated electrons deep in the p-BaSi2 light absorber layer are likely to be transferred to the p+-Si side, leading to negative values of internal quantum efficiency (IQE) at longer wavelengths. The negative IQE can be solved by extending the width of depletion region in the p-BaSi2 light absorber layer by decreasing its hole concentration. The importance of Si substrate surface morphology is also discussed.