Physics Faculty Candidate Colloquium," Colloidal Quantum Dot Photovoltaic," by Dr. Xihua Wang, University of Toronto
Science / Technology - Colloquium
Wednesday, February 22, 2012
4:00 PM-5:00 PM
Semiconductor colloidal quantum dots (CQDs), including lead chacolgenide CQDs that have tunable electronic bandgaps from infrared to visible, serve as good candidates to harvest the broad spectrum of sunlight. CQD materials enable multi-junction solar cells using a single material programmed using the quantum size effect. I will present the first CQD tandem solar cells using the size-effect tuning of a single CQD material, PbS. I made such devices by using a graded recombination layer to provide a progression of work functions from the hole-accepting electrode in the bottom cell to the electron-accepting electrode in the top cell, allowing matched electron and hole currents to meet and recombine. The reported tandem solar cell has an open-circuit voltage of 1.06 V, equal to the sum of the two constituent single-junction devices, and a solar power conversion efficiency of up to 4.2%. I will also discuss recent advances in CQD solar cells, including new insights into materials synthesis and processing, as well as thin film physics and device operation, that seek to enable this class of devices to reach their full performance potential.
Refreshments will be served in Olin Hall 118 at 3:30 p.m.
Suggested Audiences: College
Last Modified: February 8, 2012 at 9:23 AM