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We investigate the influence of the barrier type and the absorber doping on the open-circuit voltage of liquid phase-crystallized silicon solar cells on glass. It was found that the use of n-type instead of p-type substrates is the major reason for the recently reported boost of the open-circuit voltage ( $V_{\rm OC}$ ) up to values of 656 mV, which is by far exceeding the previously reported $V_{\rm OC}$ values of crystalline silicon solar cells on glass. Despite the high doping, locally, an internal quantum efficiency of $\text{90\%}$ can be achieved. Therewith, efficiencies of $\text{16\%}$ and up should be possible.

The suitability of ZnO:Al thin films for polycrystalline silicon (poly-Si) thin-film solar cell fabrication was investigated. The electrical and optical properties of 700 -nm-thick ZnO:Al films on glass were analyzed after typical annealing steps occurring during poly-Si film preparation. If the ZnO:Al layer is covered by a 30 nm thin silicon film, the initial sheet resistance of ZnO:Al drops from 4.2 to 2.2 Ω after 22 h annealing at 600 °C and only slightly increases for a 200 s heat treatment at 900 °C. A thin-film solar cell concept consisting of poly-Si films on ZnO:Al coated glass is introduced. First solar cell results will be presented using absorber layers either prepared by solid-phase crystallization (SPC) or by direct deposition at 600 °C.

Thin film solar cells based on polycrystalline silicon are an appealing option combining the advantages of thin film technologies, namely low cost, and the superior electrical properties of crystalline silicon. The specific structure aimed at in this work uses the relatively simple contacting scheme used in amorphous silicon thin film solar cells which relies on a front contact consisting of a transparent conducting oxide (TCO). Electron beam evaporation is applied as preparation method for the silicon films with high deposition rate. Solid phase crystallization (SPC) is used to crystallize the silicon films after deposition.In this work the properties of as-deposited and crystallized silicon films produced by e beam evaporation are investigated as a function of deposition temperature. It is shown that the largest crystallites are obtained for deposition around 300 °C and subsequent treatment at 600 °C, while deposition at higher temperatures leads to small crystal grains which are not changed significantly during SPC.Solar cells have been prepared on TCO-coated glass and were studied by measurements of the external quantum efficiency.