Luminescent solar concentrators (LSCs) show great promise in reducing the cost of silicon solar cells due to their potential use for high-efficiency energy harvesting. Compared to narrow absorption organic dyes, quantum dots (QDs) are a favorable approach to acquire stable LSCs. However, the use of toxic heavy metals in QDs and the small Stokes shift largely restrict their development. Here, a toxic metal-free, highly luminescent ink based on a copper(I)-halide hybrid cluster is reported, whose quantum yield (QY) exceeds 68%. Under the interaction with halohydrocarbon, CuI and phenethylamine (PEA) can be easily dissolved and the ink can be facilely acquired. The obtained film exhibits strong orange light emission with a large Stokes shift. As a proof-of-concept experiment, (PEA)4Cu4I4 has been used to fabricate LSCs. The as-prepared LSC (4 cm × 4 cm × 0.3 cm) exhibits an internal quantum efficiency (ηint) as high as 44.1%. After coupling to a solar cell, an optical conversion efficiency (ηopt) of 6.85% is acquired from this LSC. In addition, the LSC possesses high stability such as air stability, water stability, and photostability. These results demonstrate that the (PEA)4Cu4I4 film can be employed as a promising candidate for large-area and high-efficiency LSCs.
Keywords: copper(I)-halide composite; luminescence; luminescent solar concentrators; metal clusters; quantum yield.