Improving the efficiency of an industrial silicon solar cell by doping with nickel

Abstract

The possibility of adjusting the operational parameters of industrial solar cells produced by the company Suniva based on monocrystalline silicon by means of additional diffusion doping with nickel in the temperature range 700–1200 °C has been investigated. It is shown that the optimal temperature of nickel diffusion is Tdiff = 800–850 °C. In this case the value of the maximum power Pmax increases by 20–28 % in relation to the parameters of the original industrial photocell. At diffusion temperatures Tdiff > 1000 °C, a sharp decrease in Pmax occurs, which is associated with an increase in the depth of the p–n-junction due to the distillation of phosphorus atoms during high-temperature diffusion of nickel. The positive effect of diffusion alloying with nickel on the electrophysical parameters of photocells is greatest in the case when the nickel impurity clusters are in the region of the p–n-junction, i. e. with diffusion alloying to the front side of the plate. The action of electrically neutral nickel clusters is less pronounced when they are located in the region of the isotypic p–p+ transition; in case of diffusion alloying with nickel in the opposite side of the plate.

Clusters of impurity nickel atoms and their migration in the crystal lattice of silicon

“…The prospects of this direction are also due to the possible gettering of uncontrolled impurity atoms using clusters of impurity nickel atoms in the manufacture of various electronic devices, and especially in the development of high-efficiency silicon-based solar cells [8,9]. The gettering method makes it possible to increase the lifetime of minority charge carriers, and also ensures the stability of the electrical and recombination parameters of the source material, which is repeatedly subjected to heat treatment during the manufacture of electronic devices [10][11][12].…”