1Physics Department, Molecular Electronic and Optoelectronic Device Laboratory JNV University, Jodhpur, Rajasthan, India
4R & D Centre for Engineering and Science, Jaipur Engineering College, Kukas, Jaipur, Rajasthan, India
2Chemical Technology Laboratory, Department of Chemistry, University of Patras, GR-26500, Patra, Greece
3Department of Physics, Government Engineering College, Ajmer, Rajasthan
In this study, a novel solution processable small molecule SM has been incorporated into polymer solar cells based on poly(3-hexylthiophene) (P3HT) and a modified PCBM i.e. F. SM is a small molecule that contains thienothiadiazole central unit with terminal cyanovinylene 4-nitrophenyl at both sides, which were connected to the central unit via a thiophene ring. The incorporation of SM to P3HT:F blend allows not only a broad band absorption but also the tuning of the inter energy level leading to higher short circuit current (Jsc) and open circuit voltage (Voc). The bulk heterojunction (BHJ) solar cell based on P3HT:SM:F blend cast from chloroform solvent exhibits a power conversion efficiency (PCE) of approximately 4.78%. The PCE of the BHJ solar cell has been further enhanced up to 5.84% when the P3HT:SM:F blend is processed from mixed solvents (1,8-octanedithiol/chloroform). This improvement in the PCE has been attributed to the increase in the crystallinity of P3HT and SM leading to an increase in hole mobility and resulting in a balanced charge transport.
Photovoltaics, ternary bulk heterojunction solar cells, small molecule additive, processing additive
