The Effect of a Nanosize TiO x Layer on the Performance of an Organic Solar Cell

This work studies the role of a cathodic TiO x buffer layer in operation of a photovoltaic organic solar cell (OSC) based on a photoactive layer with a bulk heterojunction. Using a liquid solution to obtain a TiO x layer is of current interest for simplification of process technologies of successive formation of OSC layers. It is found that the optimum thickness of the TiO x layer is 10 nm; at this thickness, the efficiency of the OSC reaches the value of 4.36%. The effect of air oxygen on the OSC samples is studied and it is found that samples with a TiO x buffer layer undergo degradation to a lesser extent as compared to the samples with no such layer. The effect of oxygen on operation of the photovoltaic device is discussed.