Abstract Replacing the passivation layer of Si3N4 with ITO/SiOx coupled materials on the homogeneity Cz–Si based p–n junction has been fabricated by using normal device processing, and a larger short-circuit current density (49.73 mA/cm2) is obtained for this SINP architecture (semiconductor–insulator–n/p junction). The higher short-circuit current density, the mediate open-circuit voltage and filled factor may arise from an equivalent resistance of the device system. A distinct shift of the spectral response and responsivity to ultraviolet and blue wavelength was found for the shallow junction SINP cell, which was also manifested by high quantum efficiency in the same wavelength. The prominent response was still mainly assigned to be the contribution from the space charge region and base section of the cell in the experiments.