Silicon solar cell efficiency improvement employing the photoluminescent, downshifting effects of carbon quantum dots

There is a generalized trend to demonstrate higher solar cell efficiency with more affordable devices to promote their widespread utilization. One of the options explored involves the utilization of photoluminescent, down-shifting quantum structures to enable the capture of high-energy photons that tend to interact with lattice phonons rather than generate electron-hole pairs. In order to address the aforementioned perceived need, we report the synthesis and characterization of Carbon quantum dots, as well as the observed improvement in the power conversion efficiency of the produced photovoltaic devices. The quantum dot characterization included crystal structure analysis and optical properties such as: photon absorption, photon excitation and photoluminescence. The synthesized carbon quantum dots of different sizes were dispersed in a polymeric layer of PMMA 100 nm thick and incorporated on functional and previously characterized solar cells, to quantify their influence in the electrical performance of the aforementioned photovoltaic devices. We discuss the synthesis approach employed as well as the measurements collected on the quantum dots themselves and the influence on the solar cells involved.