Title:Strategies toward High Efficiency Organic and Perovskite Solar cells

TheorySpeaker:Yang Yang (Professor, Department of Materials Science and Engineering and California NanoSystems Institute, University of California, Los Angeles, California 90095, United States)

Time: Jul. 27, 2018 10:00AM

Venue:No. 320 meeting room of building 3, IOS, CAS

Abstract:In this presentation, I will firstly introduce the basic principal of photovoltaic (PV) materials and devices. Once the fundamental aspects have been laid out, I will follow with a detail discussion of organic photovoltaics (OPV) and perovskite (PVSK) PV technologies. OPV technology, utilized organic and polymer materials as the active elements, which has emerged as one of the promising photovoltaic technologies. Very recently, we obtained very high performance single-junction OPV by the synthesis of new infrared absorbing non-fullerene acceptors. These single-junction devices were certified by National Renewable Energy Laboratory (NREL), and a new record PCE of 12.6% PCE was achieved. On the other hand, perovskite solar cell is another major research in my group. In this presentation, I will report our recent understanding on methods for manipulation of the defects in perovskite solar cells. The inevitable defects at GBs were effectively passivated by additives. As a result, the PCE exceeding 21% was achieved for a planar heterojunction perovskite solar cell. Thanks to the passivated GBs, the device demonstrated significantly enhanced stability. I will also report our progresses on perovskite tandem solar cells. A high performance perovskite tandem solar cell was achieved via engineering of the interconnecting junction, where certified power conversion efficiency over 22% was demonstrated.