2015, Ganz, Britta, Ask, Maria, Hangx, Suzanne, Bruckman, Viktor, Kühn, Michael

The development of deep geothermal energy sources in Germany still faces many uncertainties and high upfront investment costs. Methodical approaches to assess the exploration risk are thus of major importance for geothermal project development. Since 2002, expert reports to quantify the exploration risk for geothermal projects in Germany were carried out. These reports served as a basis for insurance contracts covering the exploration risk. Using data from wells drilled in the meantime, the reports were evaluated and the stated probabilities compared with values actually reached.

2016, Vetter, Michael, Gawlik, Annett, Plentz, Jonathan, Andrä, Gudrun, Ribeyron, Pierre-Jean, Cuevas, Andres, Weeber, Arthur, Ballif, Christophe, Glunz, Stefan, Poortmans, Jef, Brendel, Rolf, Aberle, Armin, Sinton, Ron, Verlinden, Pierre, Hahn, Giso

Liquid-phase crystallized silicon on glass (LPCSG) presents a promising material to fabricate high quality silicon thin films, e.g. for solar cells and modules. Barrier layers and a doped amorphous silicon layer are deposited on the glass substrate followed by crystallization with a line focus laser beam. In this paper we introduce injection level dependent lifetime measurements generated by the quasi steady-state photoconductance decay method (QSSPC) to characterize LPCSG absorbers. This contactless method allows a determination of the LPCSG absorber quality already at an early stage of solar cell fabrication, and provides a monitoring of the absorber quality during the solar cell fabrication steps. We found minority carrier lifetimes higher than 200ns in our layers (e.g. n-type absorber with ND=2x1015cm-3) indicating a surface recombination velocity SBL<3000cm/s at the barrier layer/Si interface.