Surface recombination effects on the performance of n+p step and diffused junction silicon solar cells

Effect of front and back surface recombination velocity (SRV) on the performance of n⁺p step and diffused junction Si solar cells has been investigated. Assuming the impurity profile to be Gaussian in the diffused region, the influence of built-in field and field gradient on the cell performance parameters have been discussed. It has been found that relatively higher front SRV can be tolerated for terrestrial utilisation than for space application. The improvement in conversion efficiency due to the reduction in back SRV is more if the cell thickness is smaller and the junction is shallower. The benefits of a lower back SRV are limited by the value of front SRV and recombination losses in the front region. The built-in field in the front region counteracts the recombination losses at the top surface and in the front region provided the field gradient is small.