Using perovskite solar cells with tunable bandgaps for beam-splitting photovoltaic-thermal System

The beam-splitting PV-T system has great potential for solar energy production. However, few studies have been conducted on hybrid systems featuring the newly emerging perovskite solar cells. This paper proposes a novel beam-splitting PV-T system with perovskite solar cells (PSCs). PSCs with various bandgaps are fabricated for the system by replacing Iodine ion (I-) in FA1-xMAxPbI3 with different proportions of Bromine ion (Br-). The trends of the photovoltaic properties of PSC are also analyzed and validated through the characterization of perovskite films. Systems of various spectral response ranges are then simulated and optimized using the experimental data. The obtained results show that the beam-splitting PV-T system can achieve a theoretical solar-to-electric efficiency of 25.74%. This value exceeds that of the single CSP and single PSC, which are 23.97% and 17.27%, respectively. When the ratio of Br- increases, the efficiency tends to decrease. Although the introduction of Br- fails to increase the overall efficiency, the changed spectral response range brings a shift in optimum cutoff wavelength, and the efficiency only slightly decreases with a lower ratio of Br- mixing. The results of this study provide a reference for beam-splitting PV-T utilization.