Improvement in the performance of P3HT: PCBM based organic photovoltaic cell using DMDCNQI as n type dopant and buffer layer

The critical issues in the improvement of organic photovoltaic cell efficiency are excition rate, charge separation and carrier mobility. Recently, the modification of interface between metal electrode and organic active layer was widely studied in order to obtain high performance device. In general, bulkheterojunction organic photovoltaic cell blended with P3HT as an electron donor and PCBM as an electron acceptor has been used to improve the charge separation [1]. It is well known that dimethyldicyanoquinonediimine(DMDCNQI) reduce contact resistance owing to the formation of highly conducting charge transfer complex in conventional lateral type organic transistor [2], [3]. We have fabricated P3HT:PCBM based organic photovoltaic cell using DMDNCQI as n type dopant and buffer layer in order to improve the back recombination from guest material to host material and the contact resistance between metal electrode and organic active layer. In the present work, we have investigated the electrical properties of organic photovoltaic cell consisting of ITO/PEDOT:PSS/P3HT:PCBM:DMDCNQI/DMDCNQI/Al. Here, DMDCNQI was used as n type dopant having electron acceptor ability and charge transfer complex buffer layer between Al electrode and organic active layer, respectively.