Route to enhance the efficiency of organic photovoltaic solar cells - by adding ferroelectric nanoparticles to P3HT/PCBM admixture

Emerging Technologies Research Centre, Hawthorn Building, De Montfort University, The Gateway, Leicester LE1 9BH, UK

^a e-mail: spaul@dmu.ac.uk

Received: 14 May 2014
Accepted: 15 October 2014
Published online: 2 December 2014

Abstract

We have demonstrated that by adding ferroelectric nanoparticles to poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM) photovoltaic devices the relative efficiency can be increased compared to the same blend without these nanoparticles. In this work samples of 20 mg/ml concentrations of P3HT and PCBM were prepared in a 1:1 ratio and the samples prepared using ferroelectric barium titanate (BT) and strontium titanate (ST) nanoparticles in a 1:1:0.5 ratio. The samples were spin coated onto ITO coated glass with a layer of poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT:PSS). A top electrode of aluminium 1 cm² was deposited. The current-voltage characteristics of the devices were determined using a solar simulator and the absorption characteristics by UV-Vis spectroscopy. The samples with BT and ST exhibited increased absorption around 490 nm and increased open circuit voltage and short circuit current compared to the control P3HT/PCBM sample. The possible mechanism that helps to understand the increase in open circuit voltage and short circuit current is also proposed in this work.