The interest in solar cells energy arises from the fact that they are renewable, sustainable and always found across most of the earth area. So, this manuscript is dedicated to determine the photocurrent and induced conversion efficiency. The quantum dot solar cells (QDSCs) model is used to determine the dependence of photocurrent on its various parameters, such as optical generation life time, doping concentration into quantum dot, number of quantum dot layers; and surface-recombination rate. Also, the spectral response of photocurrent is theoretically calculated. The obtained results ensure that an enhancement of conversion efficiency values, up to 73%, is occurred in consequence of intrinsic region in the p–n junction that equipped by QDs layers. Superiority of the considered investigation is momentous from that the accurate values of wavelength, around 200nm, which gives maximum photocurrent is determined. Moreover, behavior of power efficiency with QDSCs parameters is investigated.