OPTICAL CONFINEMENT IN HIGH-EFFICIENCY A-SI SOLAR-CELLS WITH TEXTUREDSURFACES

The experimental spectral response and reflectance of high-efficiency a-Si solar cells are systematically investigated by using an optical s imulation based on realistic optical properties of the transparent con ducting oxide (TCO), a-Si, and metal electrode, in order to improve th e spectral response. It is shown that a practically important optical loss results from absorption by the TCO, which is enhanced by the opti cal confinement effect. This suggests that improvement in the spectral response is possible by suppressing the optical confinement in the TC O.