| 초록 |
We demonstrate highly efficient inverted polymer solar cells (iPSCs) by replacing zinc oxide (ZnO) with polyethylenimineethoxylated (PEIE) both as electron selective layer and surface modifier. The PEIE layer exhibits transparency at UV wavelength region and its ultrathin layer has no effect on light refraction or scattering, allowing more photogeneration of excitons by increasing total light absorption within the active layer. It leads to enhanced short-circuit current density (JSC) of 14.4 mA cm-2. Furthermore, smooth surface and reduced work function of indium tin oxide (ITO) electrode by PEIE layer improves compatibility between the active layer and ITO electrode and facilitates electron transport. It allows improved fill-factor (FF) of 0.68, and power conversion efficiency (PCE) of 7.02%, compared to those of the devices with ZnO (JSC = 13.4 mA cm-2, FF = 0.65, and PCE = 6.26%). |
