Photo-thermal decoupling CdTe PV windows with selectively near-infrared absorbing ATO nanofluids

Solar energy conversion and utilization are crucial for buildings. Photovoltaic windows are a promising path to improving building energy efficiency. This study proposes a novel photo-thermal decoupling cadmium telluride (CdTe) PV windows with selectively near-infrared absorbing antimony-doped tin oxide (ATO) nanofluids. The PV-ATO window features four concentrations (200/400/800/1000 ppm). Hot box experiment results show that PV-ATO windows can reduce the peak indoor air temperature by up to 2.56, 2.06, 2.86, and 2.72 degrees C respectively, while the corresponding peak illuminance is cut by 13.01 %, 12.37 %, 17.40 %, and 56.28 %. Measured transmitted spectra's correlated color temperature (CCT) of the PV-Water and PV-ATO windows are in the range of 4811.0 similar to 5271.0 K; color render index (R-a) is between 95.7 similar to 98.8; color fidelity index (R-f) is between 96.9 similar to 99.1; color gamut index (R-g) is between 97.6 similar to 99.3. Regarding color rendering performance, the PV-ATO windows can outperform conventional windows. Energy simulation results show that the comprehensive energy-saving ratios of different PV-ATO windows in Guangzhou, Changsha, Chongqing, and Wuhan can achieve -11.27 %, -20.38 %, -0.08 %, and -5.17 %. The study points to low concentrations of ATO nanofluids (200 ppm) as the recommended value.