Spring 2012 Seminars
Seminars are held in Maryland 110
at 10:45am unless otherwise noted. Refreshments precede lectures in the
ChemBE graduate student lounge at 10:15am.
Thursday, February 16, 2012
10:45 am Maryland Hall
Yan
Yao
Stanford University

Title: “Nanostructure
Design for Efficient Energy Devices”
Efficient energy conversion and storage play important
roles in the renewable energy landscape. In developing next-generation
high-performance and low-cost batteries and solar cells, significant
challenges exist at both the fundamental and practical levels. In this
talk, I will discuss how nanostructure design can provide us a unique
opportunity to manipulate the electrons, ions and photons to obtain
remarkable device performance. In the first example, I will demonstrate
a new approach to broad-band light trapping by forming
whispering-gallery resonant modes inside a spherical nanoshell
structure. Using nanocrystalline silicon as a model system, the
absorption of a single layer of 50-nm-thick spherical nanoshells is
equivalent to a 1-um-thick planar nc-Si film. Then I will show
lithium-ion battery anodes made of interconnected hollow spherical
structure are capable of accommodating large mechanical strain without
pulverization. The structure design is theoretically guided to
effectively reduce lithium-diffusion-induced stress and experimentally
verified with long electrochemical cycling life.Â
Finally, I will show the approaches of nanoscale morphology engineering
leading to efficient polymer solar cells.
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