NOVELTY - A thin film solar cell (200) with light transmission comprises substrate (210), front electrode layer (220), absorption layer (230), back electrode layer (240), light-transmittance enhancing layer (250) and encapsulation layer (260) stacked in bottom-up sequence, where part of back electrode layer is removed down to boundary level between back electrode and absorption layer to form light-transmittance regions (280), within which a light-transmittance enhancing layer with predetermined refractive index is placed.    USE - As thin film solar cell (claimed) for energy conversion.    ADVANTAGE - The light-transmittance enhancing layer has a predetermined refractive index which guides an incident light to pass through the absorption layer or the back electrode layer into the inside room and thus improves the light-transmittance of the thin film solar cell. This in turn enhances the photoelectric conversion efficiency of the resulting solar cells. Also the number of the light-transmittance regions can be reduced and this improves the light absorption of the absorption layer and enhances the light transmission of the solar cell. Therefore, the present device can resolve the problem of restricted application of the see-through solar cell and still maintain the photoelectric conversion efficiency.    DETAILED DESCRIPTION - A thin film solar cell (200) with light transmission comprises substrate (210), front electrode layer (220), absorption layer (230), back electrode layer (240), light-transmittance enhancing layer (250) and encapsulation layer (260) stacked in bottom-up sequence, where part of the back electrode layer is removed down to boundary level between back electrode and absorption layer to form several of light-transmittance regions (280), part of light-transmittance enhancing layer and part of encapsulation layer is disposed within each light-transmittance region, where light-transmittance enhancing layer has a refractive index between that of first medium overlaid by part of light-transmittance enhancing layer disposed within each light-transmittance region and that of second medium overlaying part of light-transmittance enhancing layer disposed within each light-transmittance region. The refractive index is 1-4.    DESCRIPTION OF DRAWING(S) - The figure shows a sectional view of a thin film solar cell.    Thin film solar cell (200)    Substrate (210)    Front electrode layer (220)    Absorption layer (230)    Back electrode layer (240)    Light-transmittance enhancing layer (250)    Encapsulation layer (260)    Light-transmittance region (280)