INVERTED POLYMER SOLAR CELLS USING SOL-GEL DERIVED AL-DOPED ZINC OXIDE AS ELECTRON TRANSPORT LAYER

摘要

Inverted polymer solar cells (IPSCs) have been fabricated using sol-gel derived aluminum-doped zincoxide (AZO) as the electron transport layer. The morphology and conductivity of AZO films were found to be critical tothe device performance. The experimental results indicated that by adjusting Al-to-Zn ratio of the precursor sol, theconductivity of AZO film enhanced from 4.68×10-7 to 2.76×10-4 S/cm, the root mean square roughness increased slightlyfrom 1.31 to 2.13 nm compared with the intrinsic zinc oxide film. The optimized AZO film with 1.0 at.% Alconcentration contributed to extract the electron effectively and improve the contact quality of the interface between AZOfilm and active layer, significantly enhanced the device fill factor and further improvement of efficiency by 17%compared to the device with the intrinsic ZnO. It is demonstrated that the performance of IPSCs could be effectivelyimproved by controlling Al-doping level.