Table 1

Deposition and photovoltaic-parameters for sample 1 (reference process) and samples 2 and 3. Samples 2 and 3 are the samples which show the best efficiency for the sample set where the absorber layer of the bottom solar cell was processed at 3 hPa and 5 hPa, respectively. The deposition parameters are abbreviated as follows: deposition pressure p, electrode distance d, deposition power P, silane concentration SC, and deposition rate R_D. The photovoltaic parameters describe the efficiency η, the fill factor FF, the open-circuit voltage V_oc, and the short-circuit current density J_sc.