2 μm thin film c-Si cells on near-Lambertian Al2O3 substrates

Near-Lambertian Al2O3 substrates, which have the reflectivity of almost 100% and superior optical diffusivity, were newly developed by the doctor-blade technique and 2 μm thin film c-Si cells with the large short-circuit current JSC of 15.6 mA/cm2 (photocurrent Jph of 17.5 mA/cm2) were fabricated on the substrates. These cells were prepared by ECR plasma chemical vapor deposition, electron-beam recrystallization, conventional phosphorus diffusion and ITO metallization. The optical confinement in such thin film c-Si cells on the diffuse–reflective substrates was experimentally and theoretically investigated. The theoretical computation presented a strong possibility of higher JSC beyond 30 mA/cm2.