Investigation of electrical shading loss of bifacial interdigitated-back-contact (IBC) crystalline silicon solar cells with screen-printed electrode

N-type bifacial interdigitated-back-contact (IBC) crystalline silicon solar cells were processed with screen-printed electrodes. The bifacial IBC cells resulted in a drastic decrease of the electrical shading loss at the finger region with decreasing pitch on the rear side. This loss was dominated by the width of the base region. In addition, passivation properties also affected carrier recombination in the base region. A narrower base region and smaller pitch led to higher internal quantum efficiency and low series resistance. Cell efficiency of over 22% was obtained for the bifacial IBC crystalline silicon solar cells with a base region width of 250 μm and pitch of 1250 μm. The IQE values above the emitter and base region at medium wavelengths were over 95% and 90%, respectively. Using these cells, a mini-module showing 19.4% module efficiency with 78.1% FF was created.