Atom-thin materials, devices, and structural engineering

As the thickness of the material is down to 1-nm or one atomic layer (1/1000000000 of a piece of paper), many new phenomena will emergence. Landed on a big family of atom-thin materials (e.g., graphene, BN, MoS2, other dichalcogenides, and layered oxides.), our group will focus on their synthesis and structural engineering. Combined with micro-/nano-fabrication technologies, we will make a serial of functioned devices based on atom-thin materials toward the critical problems in electronics and electrocatalysis, with an interdisciplinary branch of science.

● Synthesis and structural-engineering

We aim to synthesize monolayer, heterostructure, or wafer-scale atom-thin materials through the vapor deposition method (e.g., chemical vapor deposition-CVD or chemical vapor transport-CVT) and engineer their structures through low-temperature deep reactive-ion etching (DRIE), co-doping, phase transform, etc. For example, we have demonstrated the synthesis of high-quality few-layer MoS2, MoSe2, WS2, WSe2, and their wafer-scale films, and the structural engineering of amorphous PtSex at a single-layer limit.

Our works: Nature synthesis, 2022, 1, 245-253.

● On-chip energy devices

We will focus on the electrochemical behaviors at a single nanomaterial via the on-chipmicro-device, which helps to measure or tune the reaction interface accurately. Using the micro-/nano-fabrication technologies, this micro-device can realize that the reaction only happens at the region of interest through a micro-sizereaction window.

Our works: Nature Catalysis, 2022, 5, 212–221.

                  Nature communications, 2020, 11(1): 1-12.

                  Nature materials, 2019, 18(10): 1098-1104.

● Electronic devices

We aim to make high-performance field-effecttransistors (FETs), photodetectors based on atom-thin semiconductor materials.For example, we found a type-II band offset on varied-thickness MoSe2 and made a remarkable diode and solar-cell array. Also, we have demonstrated a monolayer suspended photodetector that completely excludes the substrate interfaces.

Our works: Advanced Materials, 2016, 28(25): 5126-5132.

                  Nano letters, 2015, 15(8): 5089-5097.

Regarding these, it behaviors many functions:

i.    Single-nanomaterial measurement, e.g., identification of the active site, engineering of site          types, more structures from 1D to 3D.

ii.   Interface/structure design, e.g., heterostructure interface, cover-layer interface, top-bottom

      electrode, interfinger electrode. For example, we demonstrate a high-efficient charge-

      injection interface (MoS2/Graphene) to elaborate the single-GB’s activity toward HER.

iii.  In-situ measurement, e.g., in-situ electronic/electrochemical measurement, time-dependent

      measurement. For example, we have demonstrated a universal “self-gating” effect in

      semiconducting catalysts.

iv.  Combination with typical structural characterization techniques, e.g., XAFS, Raman, and

     XPS, to give a three-dimensional picture of reaction (reaction, conduction, and material


v.   Extension to photoelectrochemical reaction or electrochemical sensors.

Y.HE Research Group