Indexed on: 06 Feb '18Published on: 06 Feb '18Published in: ACS Applied Materials & Interfaces
Herein, a new methodology for solution-processed ZnO fabrication on Ag nanowire network electrode via combustion reaction is reported, where the amount of heat emitted during combustion was minimized by controlling the reaction temperature to avoid damaging the underlying Ag nanowires. The degree of participation of acetylacetones which are volatile fuels in the combustion reaction was found to vary with reaction temperature as revealed by thermogravimetric and compositional analyses. Optimized processing temperature of 180°C was chosen to successfully fabricate a combustion-reacted ZnO and Ag nanowire hybrid electrode with sheet resistance of 30 ohm/sq and transmittance of 87%. Combustion-reacted ZnO on Ag nanowires hybrid structure was demonstrated as an efficient transparent electrode and electron transport layer for the PTB7-Th based polymer solar cells. Superior electrical conductivity of combustion-reacted ZnO, compared to conventional sol-gel ZnO, increased the external quantum efficiency over all absorption range while a unique light scattering effect due to the presence of nanopores in the combustion derived ZnO further enhanced the external quantum efficiency in 450-550 nm wavelength range. Power conversion efficiency of 8.48% was demonstrated for the PTB7-Th based polymer solar cell with the use of combustion-reacted ZnO/AgNW hybrid transparent electrode.