dc.description.abstract | Solar cell design is based on the composing of semiconductor layers (multijunction) with energy gap varies in each layer are arranged from highest to lowest can maximize the absorption of solar radiation intensity. Using optimum doping and optimum thickness on semiconductor can maximize the power conversion of the intensity absorbed. Absorbed intensity and amount of electrical power generated at each layer can increase the total efficiency of solar cell. Simulations carried out with 2 models, model 1 which produce different currents and model 2 that produce the same current. Semiconductor layers used is Al0.3Ga0.7As, GaAs, and Ge. Model 1 produces currents Isc at each layer of 26.4 mA, 14.9 mA, and 13 mA and total efficiency of 39.2%. Model 2 produces constant currents of 13 mA and total efficiency of 21.7%. The entire simulations were performed using 0.1367 W/cm2 of solar intensity that obtained from calculation of black body radiation spectrum of the sun's surface at 6000K | en |