Author: LetianDou

Our collaborative review article about semiconductor alloy nanomaterials is published in Nature Reviews Materials. Over the past decade there has been tremendous progress in the development of nanoscale semiconductor materials with a wide range of bandgaps, obtained by alloying different individual semiconductors. One important common feature of these materials is that their nanoscale dimensions result in a large tolerance to lattice mismatches within a monolithic structure of varying compositions or between substrate and target material, which allows the achievement of almost arbitrarily controlled variations of the alloy composition. As a result, the bandgaps of these alloys can be tuned widely without the detrimental defects that are often unavoidable in bulk materials, which have a much more limited tolerance to lattice mismatches. This class of nanomaterials could have a far-reaching impact on a wide range of photonic applications including tunable lasers, solid state lighting, artificial photosynthesis and new solar cells

The group welcomes new postdoc fellow, Dr. Yao Gao, to join us!  Yao has a Ph.D. in polymer chemistry and physics from Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. He will be initiating our organic and hybrid materials research.

The group welcomes a new undergraduate student researcher, Jiacheng Wu, joining the group. Jiacheng is a junior student in the School of Chemical Engineering.

The group welcomes new postdoc fellow, Dr. Enzheng Shi, to join us!  Enzheng has a Ph.D. in materials science from Peking University and he will be initiating our inorganic and hybrid nano materials research.

The group welcomes visiting student, Zitang Wei, from UC Santa Barbara to join us for the summer. Zitang is a senior in the chemistry department of UCSB.

The group welcomes the first undergraduate student researcher, Divya Natarajan, joining the group. Divya is a junior student in the School of Chemical Engineering and has a minor in computer science.

Letian officially starts at Purdue now. Several graduate/undergraduate student positions are available. Visiting students/scholars are also welcomed. Send CV to dou10@purdue.edu.

Our paper about inorganic halide perovskite nanowire multi-color heterojunctions has been published on PNAS. Halide perovskites are promising semiconductor materials for solutionprocessed optoelectronic devices. Here, we show that the anion-exchange chemistry can be precisely controlled in single-crystalline halide perovskite nanomaterials when combined with nanofabrication techniques. We demonstrate spatially resolved multicolor CsPbX3 (X = Cl, Br, I, or alloy of two halides) nanowire heterojunctions with a pixel size down to 500 nm with the photoluminescence tunable over the entire visible spectrum. This work is highlighted by LBNL news and many others.

Zhiqiang’s paper about Cu@Au core−shell nanowires has been published on JACS. Copper nanowire networks are considered a promising alternative to indium tin oxide as transparent conductors but are not stable in air. In this work, we developed the synthesis of ultrathin Cu@Au core−shell nanowires using trioctylphosphine as a strong binding ligand to prevent galvanic replacement reactions. The epitaxial overgrowth of a gold shell with a few atomic layers on the surface of copper nanowires can greatly enhance their resistance to heat (80 °C), humidity (80%) and air for at least 700 h, while their optical and electrical performance remained similar to the original high-performance copper.

On August 2017, Letian is moving to Purdue University, Davidson School of Chemical Engineering as an assistant professor to start his independent scientific research career. The Dou group will focus on hybrid materials and nanomaterials for energy harvesting and electronics. Several graduate student positions are available. Visiting students/scholars are also welcomed. Send CV to dou10@purdue.edu.