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36th European Photovoltaic Solar Energy Conference and Exhibition; 214-218, We examine the impact of Sorbitol admixture on the hole conductive polymer PEDOT:PSS[poly(3,4ethylenedioxythiophene):poly(styrenesulfonate)] in combination with a variation of the annealing duration. As demonstrated in a previous publication, the admixture of Sorbitol to the PEDOT:PSS dispersion is improving the transparency of the organic layer and is also improving the surface passivation. On the other hand, the contact resistance on the silicon surface tends to increase by admixture of Sorbitol. In this study, we fabricate solar cells where the PEDOT:PSS layer is used as a hole-selective contact at the cell rear (so-called ‘BackPEDOT’ solar cells). The electron-selective front is conventionally processed by means of phosphorus diffusion. The passivation of the silicon surface with PEDOT:PSS:Sorbitol shows an improvement in the passivation quality and the solar cells show an increasing open-circuit voltage Voc by increasing the annealing duration from the previously routinely applied 10 min to 60 min. The short-circuit current density Jsc of the fabricated solar cells remains unchanged for all investigated annealing durations. Importantly, the series resistance Rs (and hence the contact resistance) of the fabricated BackPEDOT solar cells show a minimum for annealing durations between 45 and 90 min. As a consequence, increasing the annealing duration led to an increased maximum energy conversion efficiency of 20.6% at one sun.