Design and simulation of a high efficiency InGaP/GaAs multi junction solar cell with AlGaAs tunnel junction

Abstract

In this work we designed and simulated an InGaP/GaAs multi junction solar cell with AlGaAs tunneling junction. We optimized the efficiency of solar cell by changing Window layer and adding back-surface field layers. The simulations are done by TCAD Silvaco software and the results are obtained by considering AM1.5 spectrum. By considering critical number of cells and also by optimizing the layer parameters, very high operation factors for multi junction solar cells are obtained. Dividing the tunneling zone to six layers, and using InAlGaP for back-surface field and window layer, the efficiency 35.5% was achieved. Finally, by increasing thickness of back-surface field layer the efficiency increased up to 36.24%. The open circuit voltage, short circuit current, and fill factor of proposed cell in the final design are 2.45 V, 17.41 mA/cm(2), and 88.70% respectively. All of the layers are lattice matched and the device can be fabricated by nowadays technology.