Biography
Letian Dou obtained his B.S. in Chemistry from Peking University in 2009. He then joined Prof.Yang Yang’s group in the Department of Materials Science and Engineering at UCLA, and obtained his Ph.D. in 2014. His doctoral research focused on the design and synthesis of conjugated polymers for organic/hybrid photovoltaic applications. His research interest also includes the synthesis of small molecules, polymer single crystals, inorganic nanostructures, hybrid materials, and related optoelectronic devices. Currently, he is a Chemist Postdoc Fellow working with Prof. Peidong Yang at the Department of Chemistry, University of California-Berkeley and awrence Berkeley National Laboratory. He has published 32 papers (including 2 Science, 1 Nature Photonics, 1 Nature Communications, 1 JACS, 1 Advanced Materials as first author) with more than 5000 citations (H index = 23). He is recipient of the prestigious MRS student awards (2014) and the Link Foundation Energy Fellowship (2013-2015).

Abstract：

Solution-processed semiconductors show great promise in energy related applications owing to their synthetic variability, low-temperature processing, and the possibility of producing light-weight, flexible, environmental-friendly, and inexpensive electronics devices. Chemistry plays an essential role for achieving new materials with better performance. I have broad research interests in both organic and inorganic chemistry to create new materials for solar cells, photodetectors,light emitting diodes, etc.
In this talk, our rational design of low-bandgap conjugated polymers for organic photovoltaic will be discussed in the first half. By developing new organic building blocks, fine-tuning the molecular weight, solid-state packing and nano-scale thin film morphology, polymers with small optical bandgap, high charge carrier mobility, and high photovoltaic performance (with two record efficiencies) are obtained. However, the fundamental limitation of low charge carrier mobility in organic semi-conductors is still there, probably due to the amorphous or semi-crystalline nature. To break the limitation, new materials with more ordered structure (higher degree of crystallinity) might be required. The other half of the presentation will be focusing on the fundamental chemistry of crystalline polymers and inorganic perovskite nanostructures for the next generation solution-processed electronics.