Abstract
In this work, we report the fabrication of indium tin oxide free organic solar cells and demonstrate the ability of niobium doped titanium dioxide (TNO) layers produced by sol-gel as feasible alternative electrode. The conductivity of the TNO was tailored by changing the layer thickness and the post-annealing conditions. Later, the crystal structure was revealed by X-ray diffraction. The post-annealing treatments were performed in a rapid thermal processing furnace under different gas atmospheres, temperatures and times. The conductivity of the samples was measured using a four-point set-up and the transparency through a UV-VIS spectrophotometer. A good sheet resistance of 181 Omega/square is achieved when the electrode was heated in an N-2/H-2 atmosphere mixture at 1000 degrees C for 10 min. TNO based organic solar cells were manufactured and their performance was evaluated by current-voltage measurements. A power conversion efficiency of 0.71% was attained. (C) 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim