The objective of this study is to develop the numerical model of InGaAs QD solar cell to describe the device characteristics. The developed model is based on Homotopy analysis which provides self-consistent and nonlinear solutions to 3D Poisson and Schrodinger equations. The exact potential and energy profile of the quantum dot accounts for the estimation of current under dark condition. The model is used in photocurrent determination of quantum dot solar cell under 1 Sun, 1.5 AM condition over a range of various solar cell parameters such as optical generation life time, quantum dot concentration and number of quantum dot layer. The quantum wavelength and quantum dot layers are used to calculate the photocurrent, recombination rate and conversion efficiency. The photocurrent has achieved its superiority with optimum quantum dot layers and wavelength. The results obtained show that the photocurrent is strongly sensitive to the above dependences and a good agreement with the experimental results was evidenced.