Suteng Qu,Jiahao Wu,Jiantao Xu,Peng Wang,Jian Song
Crystal silicon solar cells have long dominated the photovoltaic market, but their photoelectric conversion efficiencies are difficult to further improve. Although some studies have proposed to coat perovskite quantum dot downshifting film on surface of the device, there remains a lack of systematic research on the interaction between the quantum dots and their carriers. We selected three typical polymers in optical film, ethylene-vinyl acetate copolymer (EVA), polymethyl methacrylate copolymer (PMMA) and ethylene-methyl methacrylate copolymer (EMMA), and mixed them with perovskite quantum dots solutions to prepare composite films. Through component analysis, optical characterization, and theoretical calculations, we systematically explored the interaction between different polymers and perovskite quantum dots. Under protection of three composite downshifting films based on EVA, PMMA, and EMMA, the efficiencies of crystal silicon cells were increased by 0.49 %, 0.21 % and 0.81 %, respectively. As demonstrated by density functional theory calculations, it is the strong interaction between polymer chains and perovskite quantum dots make EMMA become the champion carrier for perovskite quantum dot. This study presents a promising perovskite quantum dot/polymer composite film characterized by low production costs and stable performance, demonstrating significant potential in the field of photovoltaics.
The dense surface functional groups of carbon dots (CDs) provided several reactive sites for chemical modifications that might extend applications of CDs. Herein, we tried to modify nitrogen-doped CDs chemically which obtained by pyrolysis of citric acid and β-alanine with n-dodecylamine in aqueous medium for manufacturing cationic CDs surfactant (represented with NCDs-C12). The dilute solution of NCDs-C12 performed outstandingly in declining the surface tension of water from 72.0 to 32.0 mN m −1 , which was comparable to several new types of cationic surfactants. NCDs-C12 solution (in water medium) was apt to foam, which was by far better than that of some typical surfactants at the same concentration. Additionally, NCDs-C12 was positive charged and behaved perfectly in inhibiting the growth of E. coli or S. aureus . None of any organic solvent was used during the whole procedure. We herein provided a novel route of manufacturing a surfactant with renewable substances.
危险品化学品经营许可证（带存储）