Efficient Sb₂S₃ and Low Se Content Sb₂SeS_3- Indoor Photovoltaics

Herein, the precise fabrication of Sb₂S₃ and low Se content Sb₂SeS_3- 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)/Sb₂SeS_3-(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.