Highly reproducible planar Sb2S3-sensitized solar cells based on atomic layer deposition†
A high-quality Sb2S3 thin-absorber with controllable thickness was reproducibly formed by atomic layer deposition (ALD) technique. Compared with conventional chemical bath deposition (CBD), the Sb2S3 absorber deposited by ALD did not contain oxide or oxygen impurities and showed a very uniform thickness of Sb2S3 absorbers formed on a rough surface of dense blocking TiO2/F-doped SnO2 (bl-TiO2/FTO) substrate. The planar ALD-Sb2S3 solar cells comprised of Au/Poly-3-hexylthiophene/ALD-Sb2S3/bl-TiO2/FTO showed significantly improved power conversion efficiency of 5.77% at 1 sun condition and narrow efficiency deviation, whereas the planar CBD-Sb2S3 solar cells exhibited 2.17% power conversion efficiency. The high efficiency and good reproducibility of ALD-Sb2S3 solar cell devices is attributed to reduced backward recombination because of the inhibition of oxide defects within ALD-Sb2S3 absorber and the conformal deposition of very uniform Sb2S3 absorbers on the blocking TiO2 surface by ALD process.