Welcome to the Duan Lab webpage!

Using two-dimensional layered materials and their heterostructures, we are pushing the electronic and photonic devices towards the ultimate limit of single atomic layer, creating a new generation of devices with unprecedented performance, unique functions and/or extraordinary flexibility.

Combining chemical synthesis and physical assembly approaches, we are developing powerful strategies for the hetero-integration of multi-composition, multi-structure and multi-function at the nanoscale, and by doing so, creating a new generation of integrated materials and nanosystems with unprecedented performance or unique functions to break the boundaries of traditional technologies.

Through rational design and nanoscale eintegration of highly distinct materials and functions (e.g., light harvesting, charge transport, or catalytic capabilities), we are creating new material systems for highly efficient energy harvesting, conversion and storage.

With comparable size to functional biological building blocks, nanoscale systems are ideally suited for interfacing with biological systems. We are designing nanoscale electrical and optical systems that can greatly expand our capability in probing, imaging, monitoring, and manipulating biological processes with unprecedented resolution, sensitivity and precision.

News:

Professors Xiangfeng Duan and Neil Garg have been named two of 31 National Finalists for the 2018 Blavatnik National Awards for Young Scientists.
Jun 10, 2018
Chosen from a pool of 286 nominated promising scientific researchers aged 42 years and younger from America’s top academic and research institutions, Duan is one of 11 Physical Sciences & Engineering finalists and Garg is one of ten Chemistry finalists. The finalists were selected based on their extraordinary accomplishments and their promise for the future.

From www.chemistry.ucla.edu
Tiny defects in semiconductors created ‘speed bumps’ for electrons. UCLA researchers cleared the path
Jun 10, 2018
UCLA scientists and engineers have developed a new process for assembling semiconductor devices. The advance could lead to much more energy-efficient transistors for electronics and computer chips, diodes for solar cells and light-emitting diodes, and other semiconductor-based devices.

From newsroom.ucla.edu
30 UCLA faculty on list of ‘most cited’ influential scholars
May 1, 2018
Thirty UCLA faculty members are among the most influential researchers in their fields for 2017, as determined by Claritive Analytics. The organization compiled its 2017 Highly Cited Researchers list of more than 3,000 scientists from around the world whose studies were among the top 1 percent most referenced in studies from their field. (Read more about the rankings methodology.)

From http://newsroom.ucla.edu/
UCLA researchers develop a new class of two-dimensional materials
May 1, 2018
A research team led by UCLA scientists and engineers has developed a method to make new kinds of artificial “superlattices” — materials comprised of alternating layers of ultra-thin “two-dimensional” sheets, which are only one or a few atoms thick. Unlike current state-of-the art superlattices, in which alternating layers have similar atomic structures, and thus similar electronic properties, these alternating layers can have radically different structures, properties and functions, something not previously available.

From http://newsroom.ucla.edu
2D semiconductors could make negative conductance devices
Aug 28, 2017
Researchers in the US and Saudi Arabia are the first to have observed negative transconductance (NTC) inside multilayer molybdenum-disulphide (MoS2) transistors with optimized graphene/metal hybrid contacts. The NTC behaviour comes about thanks to competition between inter-layer charge transport and charge transport through a vertical potential barrier in the MoS2. This unique effect could be exploited for making frequency doublers and phase-shift keying circuits with only one multilayer transistor – something that would greatly simplify circuit design compared to conventional technology, says the team.

From nanotechweb.org

more news

Selected Publications:

Gate-tunable frequency combs in graphene–nitride microresonators
Nature (2018) [doi]
Thickness-Tunable Synthesis of Ultrathin Type-II Dirac Semimetal PtTe2 Single Crystals and Their Thickness-Dependent Electronic Properties
Nano Lett. (2018) [doi]
Approaching the Schottky–Mott limit in van der Waals metal–semiconductor junctions
Nature 557, 696-700 (2018) [doi]
On-Chip in Situ Monitoring of Competitive Interfacial Anionic Chemisorption as a Descriptor for Oxygen Reduction Kinetics
ACS Cent. Sci. (2018) [doi]
WSe 2/GeSe Heterojunction Photodiode with Giant Gate Tunability
Nano Energy 49, 103-108 (2018) [doi]
Few‐Layer GeAs Field‐Effect Transistors and Infrared Photodetectors
Adv. Mater 1705934 (2018) [doi]
A molecular cross-linking approach for hybrid metal oxides
Nat. Mater. 17, 341-348 (2018) [doi]
Chemical synthesis of two-dimensional atomic crystals, heterostructures and superlattices
Chem. Soc. Rev. (2018) [doi]
Monolayer atomic crystal molecular superlattices
Nature 555, 231-236 (2018) [doi]
Roles of Mo Surface Dopants in Enhancing the ORR Performance of Octahedral PtNi Nanoparticles
Nano Lett. 18, 798-804 (2018) [doi]

News:

Professors Xiangfeng Duan and Neil Garg have been named two of 31 National Finalists for the 2018 Blavatnik National Awards for Young Scientists.

Tiny defects in semiconductors created ‘speed bumps’ for electrons. UCLA researchers cleared the path

30 UCLA faculty on list of ‘most cited’ influential scholars

UCLA researchers develop a new class of two-dimensional materials

2D semiconductors could make negative conductance devices

Selected Publications: