Enhancing Power Generation Efficiency of CdTe Photovoltaic Cells With Si-CQDs@PVA Thin Films: A Green and Effective Approach

Integrating carbon quantum dots (CQDs) into the CdTe photovoltaic (PV) cell is anticipated to significantly enhance its power generation performance. This improvement could lead to reduced building energy consumption and lower carbon emissions, particularly when applied to CdTe PV façades widely in modern architecture. In this study, silicon-functionalized carbon quantum dots (Si-CQDs) were synthesized using a one-step hydrothermal method, and their optical properties, morphological structure, and surface composition were thoroughly characterized. When the reaction was conducted at 180°C and maintained at room temperature for 10 h, the Si-CQDs achieved a high quantum yield of 86.67% for blue light emission with the addition of 6.6 mL of N-[3-(Trimethoxysilyl)propyl]ethylenediamine (KH-792). The Si-CQDs exhibited stable fluorescence over a 2-month storage period and 48 h of ultraviolet (UV) irradiation. Subsequently, Si-CQDs@PVA thin films were fabricated using a scraping coating method to investigate their effects as a luminescent downshifting (LDS) layer on the performance of CdTe PV cells. It was found that with the application of a 1.5-mL thin-film slurry, the short-circuit current density (J_sc) increased from 0.82 to 0.84 mA·cm⁻², and the maximum power output (P_max) increased from 0.192 to 0.201 W, corresponding to a 4.76% enhancement in power generation efficiency.