Improved Blue Response of Amorphous Silicon Alloy Solar Cells

Abstract

ABSTRACTA two-layer MgF2/ITO antireflection (AR) coating has been used to reduce the reflection losses from the surface of a hydrogenated amorphous silicon alloy solar cell. This has resulted in a higher efficiency device primarily due to an improved blue response. The relative thicknesses of the MgF2and ITO layers have been tailored to give the highest overall quantum efficiency (Q) values, which are higher than that obtained with a single-layer antireflection coating. Typically, the 0 value at 400 nm (Q400) has been increased from 0.58 to 0.68 for a single a:SiH cell. Incorporation of the double-layer AR coating in conjunction with μc-SiC p-layer has yielded Q400value of 0.77. The total current density obtained by adding the individual contribution of the component cells of a dual bandgap triple amorphous silicon alloy solar cell has been increased from 21.90 to 23.27 mA/cm2using the double-layer AR coating.