Silicon quantum dots prepared by electrochemical etching and their application in solar cells

We demonstrated that silicon quantum dots (SiQDs) with bright photoluminescence (PL) were produced by an electrochemical etching process. The PL intensity of functionalized porous silicon (PSi) with respect to time was investigated. Stable surface-modified SiQD dispersions were obtained using thermally induced hydrosilylation with octadecene. Various concentrations of SiQDs were spin-coated on Si solar cells (SiSCs) and perovskite solar cells (PSCs) to improve the performance of the solar cells. The external quantum efficiency (EQE) of the optimal sample showed that the current density increased from 37.4 to 39.2 mA/cm². The EQE increased to 98% compared with the initial value of 95% in the visible spectrum region. The experimental results showed that the reflectivity of the solar cells could be reduced by applying a certain amount of SiQDs on different solar cells. The power conversion efficiency (PCE) of SiSCs increased by 0.81%, and the PCE of PSCs increased by 0.61% after coating with SiQDs. Furthermore, when exposed to intense radiation in a UV aging chamber, both SiSCs and PSCs experienced reduced PCE loss by 0.11% and 0.62%, respectively, owing to the application of SiQDs on their surface.