Optimal band gaps for InGaN single and double junction solar cells

The objective of this paper is to find out the optimum band gap energy for InGaN single and double junction solar cells providing the best efficiencies. The different physical phenomena occurring in the solar cells structures were taken into account. InGaN-based single and double junction solar cells were simulated with different band gap energy taking into account the dependence of the physical, optical and electrical properties on the InGaN material composition. The InGaN solar cells structures were also optimized for each band gap. The investigation results show that the best efficiencies of the single and double junction InGaN solar cells of about 26.51 % and 34.93 %, respectively, were obtained for the optimized In 0.622 Ga 0.378 N (1.39 eV) and In 0.49 Ga 0.51 N/In 0.74 Ga 0.26 N (1.73 eV/1.13 eV) structures. Furthermore, our obtained results were compared with those reported by the others published works.