Hydrogen passivation effect on the conversion efficiency of Si solar cells by low-energy proton implantation

This work illustrates low energy hydrogen ion implantation of Si solar cells just before the co-firing process. The cells were hydrogen implanted on the SiNx layer in order to improve the surface passivation and prevent the surface damage by the ion implantation beam. To control the depth of hydrogenated layer, the incident angle of hydrogen ion beam was tilted about 7° from the 〈0 0 1〉 direction and was also twisted 22.5° from the 〈1 1 0〉 direction. The cell implanted with low implantation dose of 1013 H+/cm2 and energy of 4 keV showed highest efficiency of 18.02% due to the excellent surface passivation property, high photocurrent and minority carrier lifetime as compared to the reference and other implanted silicon solar cells.157