A computational model is developed to investigate the effect of vertical composition gradient on the photovoltaic properties of organic photovoltaic cell based on poly (3-hexylthiophene) (P3HT) and [6,6]-phenyl C 61-butyric acid methyl ester (PCBM). When the photovoltaic properties of model devices with systematic variation of vertical composition distribution are calculated by using this model, it is found that the efficiency increases almost linearly as the concentrations of P3HT and PCBM become richer near anode and cathode, respectively. The larger exciton generation near anode due to enrichment of P3HT near the anode contributes mainly to an increase of the device efficiency by compensating the lower hole mobility of P3HT with shorter pathway to the anode.
Bibliographical noteFunding Information:
The authors thank the Ministry of Education, Science and Technology (MEST), Korea for financial support through the Global Research Laboratory (GRL) program, and the World Class University (WCU) programs.
ASJC Scopus subject areas
- General Physics and Astronomy