Evaporated and solution deposited planar Sb2S3 solar cells: A comparison and its significance

Sb2S3 is an alternative emerging material for chalcogenide solar cells. In this paper, we compare planar solar cells in which the Sb2S3 absorber was deposited by either thermal evaporation or a solution based process. The planar inorganic solar cell with evaporated Sb2S3 has an efficiency of 1.7%. This is much higher than the efficiency of 0.8% for solution deposited Sb2S3, and the highest known reported efficiency for a planar Sb2S3 solar cell with a CuSCN hole conducting layer. The evaporated Sb2S3 film is sulfur-rich, which results in flattening of the film surface after annealing at 300 degrees C, thereby reducing the likelihood of contact between the Sb2S3 and gold contact. In addition, the crystal size of the evaporated Sb2S3 film is about 30% larger than that of the solution deposited Sb2S3 and has different preferential crystal planes. These features make evaporation a promising deposition method for flat solar cells made from sulfur-based semiconducting materials. [GRAPHICS] Cross section image of the evaporated Sb2S3 solar cell with labels for each layer. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim