Solution processable buffer layer for organic photovoltaic devices

Abstract

In the past few decades, a tremendous growth has been seen in the interest of organic photovoltaic (OPV) devices study due to their ease of processing and potential for low cost fabrication. In an OPV cell, one of the key components is its buffer layer that

connecting the active photovoltaic material to the electrodes, since the effectiveness of the carrier injection from the active photovoltaic material layer into the electrode layer has a strong influence on the overall energy conversion efficiency of the OPV device. In this project, a study related to solution processable anode hole transport buffer layer for bulk-heterojunction (BHJ) polymer solar cells has been conducted to investigate the influence of different anode buffer layers on the performance of OPV cells based on blends of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-buytyric acid methyl ester (PCBM). An indium tin oxide (ITO) glass is used as the anode layer. Compared to the commonly used poly(ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) buffer layer, a novel hybridized MoO3-PEDOT:PSS composite anode interfacial layer

proposed in this work shows an improved power conversion efficiency, up to 4.27%. Results from a substantial number of devices have indicated that this improvement is statistically consistent and devices adopting this proposed anode buffer layer

demonstrate enhanced stability as well as reliability. In addition, anode buffer layers for ITO-free polymer solar cells have also been investigated in this project. A power conversion efficiency of 2.33% has been achieved for ITO-free polymer solar cells with

1cm2 active area, which is comparable to OPV devices using ITO as the anode layer.