Efficient Sb2S3 and Low Se Content Sb2SeyS3–y Indoor Photovoltaics

Herein, the precise fabrication of Sb2S3 and low Se content Sb2SeyS3–y indoor photovoltaics is reported, and a measurement protocol for photovoltaic performance is suggested and applied. Insertion of the SnO2 buried layer decreases the thickness and parasitic absorption of the CdS layer. The introduction of minor Se into Sb2S3 and the use of spiro-OMeTAD:TMT-TTF improve the charge transport of indoor photovoltaics. Using a white light-emitting diode (LED) under illuminance of 1000, 500, and 200 lx with color temperatures of 3347 and 6103 K, indoor photovoltaics with fluorine doped tin oxide (FTO)/SnO2 (17 nm)/CdS (20 nm)/Sb2S3/spiro-OMeTAD:TMT-TTF/Au exhibit power conversion efficiency (PCE) values of 17.59, 16.66, 16.44, 16.56, 15.50, and 14.07%, respectively. Indoor photovoltaics with FTO/SnO2 (17 nm)/CdS (20 nm)/Sb2SeyS3–y(Sb/S/Se = 1:1.42:0.06)/spiro-OMeTAD:TMT-TTF/Au achieve PCE values of 18.53, 17.62, 17.07, 17.30, 16.24, and 15.38%, respectively. The PCE values of 17.59, 16.66, and 16.44% are the highest values reported for Sb2S3 indoor photovoltaics, and the other PCEs are all reported for the first time. Considering the trillion-dollar-sized market from the Internet of Things (IoT), this work can further bring an unprecedented thrust to the development of self-powered IoT devices by harvesting energy from indoor photovoltaics, thereby realizing the recycling of photon energy and reducing the use of batteries and the emission of CO2.