（The Department of Chemistry at the University of California, Berkeley）
报告题目：New generation solution-processed solar cells based on polymers and quantum dots
In recent years, solution processed materials such as polymers and quantum dots have emerged as the new building blocks for the next generation of photovoltaic devices that will be amenable to roll-to-roll printing technologies. However, power conversion efficiencies and operational lifetimes of these devices are still low. We demonstrated efficient polymer/fullerene solar cells by applying postproduction annealing, using optical spacer and adding high boiling point solvents. We systematically studied the device morphology and revealed that this excellent photovoltaic performance depends strongly on the nano-scale phase separation network of the polymer and fullerene components. I will also present my work on inorganic nanocrystal solar cells. I designed and synthesized ternary PbSxSe1-x quantum dots as novel photovoltaic materials. Photovoltaic devices made using these alloy quantum dots are more efficient than either pure PbS or pure PbSe based nanocrystal devices. In order to further improve device performance, monodisperse ultra small PbSe quantum dots were synthesized and used for nanocrystal array solar cells. I achieved a remarkably high power conversion efficiency of 4.5% for these small PbSe nanocrystal based devices.