PIPages
Labs

Keji Lai

University of Texas at Austin, TX·Physics

Many technologies depend on what happens when light hits a material: solar cells, light detectors, LEDs, and possibly future memory chips. The lab uses electrical measurements at very small scales to study new two-dimensional (2D) materials, crystals only one or a few atoms thick.

Fields

Physics

Materials Science

Engineering

Topics

excitons

trions

two-dimensional materials

Grants
2 known grants, through Aug 2027

What they work on

  1. Measure the effective permittivity of excitons in monolayer semiconductors using cryogenic laser-illuminated microwave impedance microscopy, a scanning probe that senses local electrical response under light.
  2. Visualize the transport and diffusion of excitons and trions in 2D monolayers and heterostructures, and compare the electrical properties of excitons within one layer to those spanning two layers.
  3. Probe local properties, correlation and topology of exciton insulators and moiré excitons in twisted-layer moiré superlattices, with high spatial, temporal and spectral resolution.
  4. Test whether heterostructures of magnetic van der Waals layers and ferroelectric van der Waals or oxide materials show strongly enhanced magnetoelectric coupling, using machine-learning predictions validated by synthesis and characterization.

More about the research

It examines both how these materials respond to light and how their electric and magnetic properties can be combined.

Why it matters

Understanding how excitons move and break apart in atom-thin semiconductors could help engineers design better solar cells, photodetectors and light-emitting devices from 2D materials, including devices that work under intense light. Artificial multiferroics with strong magnetoelectric coupling could enable compact, power-saving memory and low-power electronics in which a voltage controls magnetism.

Known grants

From NIH and NSF research grants. Labs often have other funding we can't see.

Spatially, Temporally, and Spectrally Resolved Electrical Probing of Optical Excitations

NSF · Sep 2024 – Aug 2027

Collaborative Research: DMREF: Accelerated Discovery of Artificial Multiferroics with Enhanced Magnetoelectric Coupling

NSF · Oct 2021 – Sep 2026

Closest labs

Christian Binek

University of Nebraska-Lincoln, NE·Physics

Engineer interfaces in oxide and van der Waals layered stacks to control magnetic and electric order, defects and spin textures, aiming at memristive devices and neuromorphic, brain-inspired computing.

Conrad Ingram

Clark Atlanta University, GA·Materials Science

Use theoretical calculations to predict mechanisms and guide the design of oxide-oxide interfaces in which electric fields control magnetism, aiming for higher magnetoelectric coefficients at room temperature.

Leonid Butov

University of California-San Diego, CA·Physics

Study spin transport carried by indirect excitons, electron-hole pairs split across separate semiconductor layers, using optical measurements in layered heterostructures.

The school

University of Texas at Austin: 49 labs on PI Pages, $1.1B a year on research, 871 research doctorates a year.

More about University of Texas at Austin

Reach out

A start for your email. Fill in the brackets.