Balancing the Energy levels and Charge Mobility of the Conjugated Polymer PM6 by a Third Component to Enable Efficient Organic Solar Cells

The notable wide bandgap conjugated polymer (WB-CP) PM6 was optimized by introducing the third component of 4,8-bis(tri-iso-propylsilicylethynyl)benzo[1,2-b;4,5-b']dithiophene (BDT-TIPS). With the increase of the BDT-TIPS contents in the WB-CPs, the maximal absorption peaks and on-set-band gap wavelengths of the WB-CPs, are gradually blue-shifted, alongside the successive deepening of the highest occupied molecular orbital (HOMO) from -5.54 eV to -5.68 eV. The more efficient OSCs with PCEs of 16.38 % were achieved in the OSCs from PM6-TIPS5 paired with Y6 in contrast to that of 15.76 % for PM6 : Y6 based OSCs under AM1.5 sun stimulation (100 mA/cm(2)). Besides that, the investigations of the charge transporting, exciton dissociation and the recombination characteristics etc., were implemented and sugessted the improvement of the PCEs of PM6-TIPS5 based OSCs was mainly ascribed to the subtly balancing of the HOMO energy levels and charge mobility of the PM6 by optimization of the feed ratio of the BDT-TIPS.