MIS-IL solar cells are potentially low-cost devices, due to their simplicity and avoidance of the high-temperatures in their fabrication processing. In addition, inversion-layer (IL) solar cells are demonstrated to have higher collection efficiencies at short wavelengths. The spectral response of MIS-IL solar cells has been measured in the wavelength range 340-1100 nm. From these measurements, the external and internal quantum efficiencies have been determined. Also, a comparative study of the quantum efficiencies of inversion layer and diffused junction cells has been carried out. The IL cell has a higher collection-efficiency for carriers generated by ultra-violet light than the conventional p-n junction solar cell. These results reveal one of the important advantages of IL solar cells, Also, it can be seen that IL solar cells can be improved by surface texturing in a similar way to a conventional diffused solar cells.