Computer analysis of microcrystalline silicon hetero-junction solar cell with lumerical FDTD/DEVICE

Abstract

The computer analysis of tandem solar cell, c-Si/a-Si:H/[Formula: see text]c-SiGe, is studied within Lumerical FDTD/Device 4.6. The optical characterization is performed in FDTD and then total generation rate is transported into DEVICE for electrical characterization. The electrical characterization of the solar cell is carried out in DEVICE. The design is implemented by staking three sub cells with band gap of 1.12[Formula: see text]eV, 1.50[Formula: see text]eV and 1.70[Formula: see text]eV, respectively. First, single junction solar cell with both a-Si and [Formula: see text]c-SiGe absorbing layers are designed and compared. The thickness for both layers are kept the same. In a single junction, solar cell with a-Si absorbing layer, the fill factor and the efficiency are noticed as [Formula: see text], and [Formula: see text]. For [Formula: see text]c-SiGe absorbing layer, the efficiency and fill factor are increased as [Formula: see text] and [Formula: see text], respectively. Second, for tandem thin film solar cell c-Si/a-Si:H/[Formula: see text]c-SiGe, the fill factor [Formula: see text] and efficiency [Formula: see text] have been noticed. The maximum efficiency for both single junction thin film solar cell c-Si/[Formula: see text]c-SiGe and tandem solar cell c-Si/a-Si:H/[Formula: see text]c-SiGe are improved with check board surface design for light trapping.