Solution Processable D-A Small Molecules for Bulk-Heterojunction Solar Cells: A Review Sharma G.D.1,2,*, Mikroyannidis J.A.3 1Department of Physics, Molecular Electronic and Optoelectronic Device Laboratory, JNV University, Jodhpur-342005, Rajasthan, India 2R & D centre for Engineering and Scicence, Jaipur Engineering College, Kukas, Jaipur, Rajasthan, India 3Chemical Technology Laboratory, Department of Chemistry, University of Patras, GR-26500, Patras, Greece *E-mail: sharmagd_in@yahoo.com
Online published on 10 August, 2015. Abstract Solution processed bulk heterojunction (BHJ) organic solar cells (OSCs) have gained wide interest in past few years and are established as one of the leading next generation photovoltaic technologies for low cost power production. Power conversion efficiencies up to 6% and 6.5% have been reported in the literature for single layer and tandem solar cells, respectively using conjugated polymers. A recent record efficiency about 8.13% with active area of 1.13 cm2 has been reported. However Solution processable small molecules have been widely applied for photovoltaic (PV) devices in recent years because they show strong absorption properties, and they can be easily purified and deposited onto flexible substrates at low cost. Introducing different donor and acceptor groups to construct donor acceptor (D-A) structure small molecules has proved to be an efficient way to improve the properties of organic solar cells (OSCs). The power conversion efficiency about 4.4% has been reported for OSCs based on the small molecules. This review deals with the recent progress of solution processable D-A structure small molecules and discusses the key factors affecting the properties of OSCs based on D-A structure small molecules: sunlight absorption, charge transport and the energy level of the molecules. Top Keywords Small molecules, bulk heterojunction, photovolatic devices, donor-acceptor structure. Top |