Chemical bath deposition of Sb2S3 films with the uniform S distribution for efficient indoor photovoltaics

Antimony sulfide (Sb2S3) is an impressive absorber material for indoor photovoltaics and the bandgap of 1.7 eV can well match with the emission spectra of the white light-emitting diode (LED). Herein, the high quality Sb2S3 films with uniform S distribution, high S content, low Sb-O content and [hk1] preferential orientation can be successfully prepared by the supplemental adding Na2S2O3 strategy during the chemical bath deposition process. The Sb2S3 solar cells show the power conversion efficiency (PCE) of 7.73 % using the solar simulator (Air mass number 1.5, 100 mW & sdot;cm-2) and 18.16 % using the warm white LED with color temperature of 3347 K and illuminance of 1000 lux. The PCE of 18.16 % is the highest value of Sb2S3 indoor photovoltaics and the result demonstrates that the supplemental adding Na2S2O3 strategy during the chemical bath deposition process is an efficient path to prepare uniform S distribution Sb2S3 films.