Tandem solar cells have demonstrated the potential to increase the efficiency of solar energy conversion. The detailed balance principle introduced by Shockley and Queisser 1961 was later applied by De Vos 1980 to study the tandem structures. Although the mathematical formulation is simple, the mathematical resolution is rather complex but fairly accurate. In this work I describe a simple Monte Carlo (MC) technique to determine the detailed balance limiting efficiency for tandem solar cell stacks. This statistical method used a simple sampling scheme which is adequate to resolve a complex equation system that is depicting a large number of multi‐junction without any further approximations. In current‐matched tandem solar cells, the band gap of each sub‐cell has to be chosen so that the current flowing through each of the sub‐cells is the same. Finding from this study fcus on10 stacked junctions; the algorithm can be applied to a larger number of sub‐cells. The simulation is carried out with four different conditions; under black body, AM1.5G, AM1.5D spectrums and maximum concentration. The method employed in this study provides a useful tool for researchers to assess the optimum band gap arrangements of current constrained solar cell stacks together with a predicted efficiency limit. The results claim that the application of MC technique is in agreement with the finding from previous studies.
