Reducing parasitic absorption and recombination losses in silicon solar cells through transition metal doped glass frit

Efficient electron selective contacts, smoother rear silicon surface and passivation of silicon-electrode interfaces could reduce parasitic light absorption and electron-hole recombination. Therefore, they are necessary for high conversion efficiency in silicon solar cells. In this work, a novel transition metal doped glass frit is fabricated and introduced into pristine Al paste. As a result, the average power conversion efficiency (PCE) of cells is improved from 17.9 to 18.3%. Combining several results, the improvement can be attributed to three key factors: (a) a thicker back surface field (BSF) layer that blocks electrons; (b) a smoother rear silicon surface which leads to less parasitic absorption; and (c) glass frit coating on aluminum particles which may facilite hole-transfer from silicon layer to aluminum electrode.