An intense NIR emission from Ca14Al10Zn6O35: Mn4+, Yb3+ via energy transfer for solar spectral converters

To date, most current reports on the development and optimization of solar spectral converters have described the utilization of energy transfer among rare-earth ions. Here, we introduce non-rare- earth ion Mn4+ to transfer energy to Yb3+, which can exhibit strong near-infrared luminescence. It can harvest UV-blue photons and exhibits intense NIR emission of Yb3+ around 1000 nm, perfectly matching the maximum spectral response of Si solar cells. It demonstrates for the first time that efficient energy transfer occurs with a decrease in the excited state lifetime and red photoluminescence (PL) from Mn4+ with increasing Yb3+ concentration. These results demonstrate that the Mn4+ ions can be an efficient and direct sensitizer harvesting UV-blue photons. It could provide new avenues for developing harvesting Si-based solar cells.