Quantum Dot as a Mechanism to Supress Charge Recombination in Polymer Solar Cell
Abstract
Effective light trapping mechanisms in thin film polymer solar cells (PSC) are leveraged by employing group II-VI semiconductor quantum dots. Core-shell semiconductor quantum dots ( CdxS/Zn1-xS SQD) were synthesised via the microwave irradiation method. The SQDs were incorporated into the electron transport layer of PTB7:PC71BM blend PSC to assist in light trapping and charge collection processes. The measured device parameters suggest that the inclusion of SQD has significantly enhanced the solar cell's power conversion efficiency (PCE) due to improved energy transfer, exciton generation, and charge collection processes in PSCs. Moreover, the performances of the solar cells are found to be dependent on the concentration of SQD in the transport layer. Hence, the best efficiency recorded was 7.13% at an optimal concentration of 0.375 wt.%, which is an increment in PCE by nearly 23%.