We present an interdigitated back-contact silicon heterojunction system designed for liquid-phase crystallized thin-film (~10 μm) silicon on glass. The preparation of the interdigitated emitter (a-Si:H(p)) and absorber (a-Si:H(n)) contact layers relies on the etch selectivity of doped amorphous silicon layers in alkaline solutions. The etch rates of a-Si:H(n) and a-Si:H(p) in 0.6% NaOH were determined and interdigitated back-contact silicon heterojunction solar cells with two different metallizations, namely Al and ITO/Ag electrodes, were evaluated regarding electrical and optical properties. An additional random pyramid texture on the back side provides short-circuit current density (jSC) of up to 30.3 mA/cm2 using the ITO/Ag metallization. The maximum efficiency of 10.5% is mainly limited by a low of fill factor of 57%. However, the high jSC, as well as VOC values of 633 mV and pseudo-fill factors of 77%, underline the high potential of this approach.