High-efficiency solar cell using a thin porous silicon layer

The performance improvement of solar cells due to the formation of a porous silicon layer on deep-junction n(+)/p silicon structures has been investigated. The photovoltaic properties of two identical sample groups with and without porous silicon layer are compared. More than a 50% improvement in I-sc and about a 5% increase in V-oc was demonstrated in structures with PS layer. No change in the fill factor was observed. The performance of the porous silicon solar cell has been found to be sensitive to the PS layer thickness. Optimal thickness was determined using the electrical measurement. The main result is that the photovoltaic energy conversion efficiency of solar cells can be increased by the PS layer. This low-cost PS formation process can be applied in the photovoltaic cell technology as a standard procedure. (C) 1997 Elsevier Science S.A.