서강대학교

초록/요약 도움말

β-NaYF4:Yb3+, Er3+ upconverting microparticles (UCMPs) were synthesized by a modified hydrothermal method. In the hydrothermal reaction using sodium citrate as a chelating agent, the initial pH value of the solution critically affected on the morphology and the upconversion efficiency of the prepared β-NaYF4:Yb3+, Er3+ UCMPs. At pH 3.13, β-NaYF4:Yb3+, Er3+ UCMPs with hex-agonal-tube morphology were produced. As the pH was changed to basic condi-tions, the particles with increased diameter and decreased length were produced. At pH 11.20, β-NaYF4:Yb3+, Er3+ UCMPs with hexagonal-plate morphology were produced. Different morphologies of the prepared β-NaYF4:Yb3+, Er3+ UCMPs showed different upconversion efficiency. β-NaYF4:Yb3+, Er3+ UCMPs prepared at pH 3.13 showed the highest upconversion efficiency due to their single crystalline quality. For the application as the upconverting reflection film for dye-sensitized solar cell (DSSC), hexagonal-tube β-NaYF4:Yb3+,Er3+ UCMPs were evenly dispersed on the surface of a glass substrate. The prepared film was placed on the back side of the Pt-counter electrode for efficiency measurement of the DSSC. Thickness of the film also critically affected on the efficiency increase of DSSC, and showed a maximum increase of efficiency from 6.73% to 7.70% by 0.97%.