Highly Efficient Semitransparent Solar Cells with Selective Absorption and Tandem Architecture

Semitransparent (ST) photovoltaics (PVs) with selective absorption in the UV or/and near-infrared (NIR) range(s) and reduced energy losses, are critical for high-efficiency solar-window applications. Here, a high-performance tandem ST-PV with selected absorption in the desirable regions of the solar spectrum is demonstrated. An ultralarge-bandgap perovskite film (FAPbBr(2.43)Cl(0.57), E-g approximate to 2.36 eV) is first developed to fulfil efficient selective absorption in the UV region. After optimization, the corresponding ST single junction (SJ) PV exhibits an averaged transmittance (AVT) of approximate to 68% and an efficiency of approximate to 7.5%. By sequentially reducing the visible absorbing component in a low-bandgap organic bulk-heterojunction layer, an ST-PV with selective absorption in the NIR is achieved with a power conversion efficiency (PCE) of 5.9% and a high AVT of 62%. The energy loss associated with the SJ ST-PVs is further reduced with a tandem architecture, which affords a high PCE of 10.7%, an AVT of 52.91%, and a light utilization efficiency up to 5.66%. These results represent the best balance of AVT and PCE among all ST-PVs reported so far, and this design should pave the road for solar windows of high performance.