Performance enhancement in organic-inorganic hybrid photovoltaic cells by adding a carbon-nanostructure interface layer

Abstract

Inverted photovoltaic configuration overcomes the stability problem in conventional polymer photovoltaic device. However, the charge transport property at the organic-inorganic junctions is one of the important issues affecting the performance of this type of photovoltaic cells. To solve the problem, we deposit a carbon-nanostructure layer, C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">60</sub> , on the inorganic ZnO-nanorod array surface to be in contact with a polymer blend, poly(3-hexylthiophene):(6,6)-phenyl C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">61</sub> butyric acid methyl ester (P3HT:PCBM), forming a ZnO/C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">60</sub> /P3HT:PCBM/Ag device. In the presence of the C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">60</sub> layer, both the short circuit current (J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SC</sub> ) and open circuit voltages (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OC</sub> ) are improved leading to an enhancement in the power conversion efficiency from 1.3% to 2.1%. The role of the C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">60</sub> layer is to assist the exciton separation and transport the electrons to the collecting electrode.