Topic: Probing charge dynamics in organic solar cells using optical spectroscopy
Speaker: Dr. Ciyong Zhou, the Hong Kong University of Science and Technology
Time: 11:00, April 28, 2017
Venue: Room 502, Building of State Key Laboratory of Luminescent Materials and Devices, Wushan Campus
Abstract:
The power conversion efficiency of a bulk-heterojunction organic photovoltaic blend is governed by charge separation and recombination processes at short timescales. A physical model of these processes can be developed using optical spectroscopy techniques with femtosecond resolutions, such as transient pump-probe spectroscopy. In this talk, I will review the use of optical spectroscopy for understanding charge dynamics in organic photovoltaic blends, and discuss how this technique was used to reveal the important role of spin in charge recombination1,2. This spin recombination pathway can significantly limit the solar cell efficiency, and is energetically favored for systems that are designed to have low photovoltage losses3.