Effect of ZnO Double Layer as Anti-Reflection Coating Layer in ZnO Dye-Sensitized Solar Cells

Abstract

Dye-sensitized solar cells based on ZnO double layer anti-reflection coating (DLARC) thin films are investigated. The ZnO DLARCs were prepared by stacking two different ZnO morphologies prepared by two different techniques including rf-magneton sputtering (rf-ZnO) and sparking technique (sp-ZnO). The device using rf-ZnO as the bottom layer and sp-ZnO (3 cycles) as the top one exhibits short circuit current density (Jsc) of 5.80 mA/cm2 and the maximum power conversion efficiency (PCE) of 1.88%, which is higher than that of the device stacking in reverse order and the device using ZnO single layer anti-reflection coating (SLARC). The main enhancement of PCE is attributed to the reduction of light reflection at the substrate surface. This leads to the increase of Jsc and the efficiency improvement of DSSCs.