Characterization of novel mono- and bifacially active semi-transparent crystalline silicon solar cells

This paper presents the latest cell results for semi-transparent mono- as w ell as bifacially active POWER ((Polycrystalline Wafer Engineering Result) solar cells of different cell sizes on Cz and multicrystalline silicon subs trates. Top efficiencies of 10.4% for monofacial and 12.9% for bifacial cel ls are reported. Attention has been paid to apply a fully industrially comp atible production process. It uses dicing saw based mechanical texturizatio n of the front and rear side of the silicon wafer and screen printing metal lization, In the POWER solar cell concept, perpendicular grooves on the fro nt and rear side create holes with a variable diameter at their crossing po ints. This results in a partial optical transparency of the solar cell. In this study, holes of 200 mu m diameter lead to a transparency of 16-18% on average for the total cell area. The cell characteristics for the different cell types are compared by means of illuminated and dark current-voltage (I-V), spectral response, and Lase r Beam Induced Current (LBIC) measurements. While bifacial POWER cells need a more elaborate production process, they reveal better I-V characteristic s and a higher efficiency as compared to monofacial cells. This is mainly e xplained by a better surface passivation due to an active emitter and a pas sivating silicon nitride ARC both on the front and rear surface.