Modelling was used to determine how reflexively fixed AlxGa1-xAs/InP/Ge MSCSs respond to changes in SI and temperature. To model energy generation, a MATLAB code was used, while a PC1D code handled data reception and transmission of a z-matrix spectrum. The ISR on the leading z-matrix was obtained by increasing spectrum of AM1.5d by ranges of SIMF moves from 1 to 200 suns. In every modelling, temperatures between 25 to 100oC were used. The results of the simulation reveal that the VOC and efficiency of the SCs react linearly with respect to temperature variations, deviation from random response of SCEs brought about by SIMF changes. According to the simulation outcomes, the optimum performance is reached at a functioning temperature of 25°C and an irradiance spectrum exposure of 100 suns.