This thesis develops a model in Silvaco International's Virtual Wafer Fabrication (VWF) environment to assist advanced solar cell developers in designing more efficient solar cells intended for use in space. The complete model is intended to accurately predict the properties and characteristics of an existing state-of-the art multiple junction solar cell. This model should also be robust yet flexible in order to facilitate future modification and expansion. A specific dual junction cell, constructed of GaInP2/GaAs/Ge and displaying 24- 26% efficiency at Air Mass Zero sun equivalency, was chosen as the baseline for this model and the characteristics of this cell and the materials that comprise it are explored and discussed. Basic building block models are constructed and displayed. Additionally, the intended structure of the eventual model is displayed and possibilities for future work are described.