The potential of PIN triple-junction Si-based thin film solar cells incorporatiing microcrystalline silicon as sub-cell(a-Si/a-SiGe/μc-Si) with a high conversion efficiency was estimated in terms of transparent conductivity oxide(TCO) substrate glass.Only varying μc-Si bottom-cell thickness,it is found that the performance of the triple-junction cells is not affected due to the mid-cell current limit.The quantum efficiency(QE) results of the sub-cells reveal that the ZnO back reflection(BR) laye...