Quantum photocells for next generation solar energy harvesting
In semiconductor photovoltaics, photoconversion efficiency is governed by a simple competition: the incident photon energy is either transferred to the crystal lattice (heat) or transferred to electrons. Quantum electronic systems promise to tip the balance in this competition by simultaneously limiting energy transfer to the lattice and enhancing energy transfer to electrons. The QMO lab explores new materials that provide the means to surpass the standard limit for photoconversion efficiency.
Ultrafast spatio-temporal probes of atomic layer semiconductors
Using ultrafast photocurrent and luminescence spectroscopy, the QMO lab explores the fundamental spin, valley, and charge degrees of freedom accessible in the atomic layer semiconductors. By incorporating spatially scanned laser excitation, spatio-temporal optoelectronic measurements will be utilized to prepare and probe optically induced transient exciton populations.
Magneto-electronic photocurrent and photoluminescence of graphene
It has now been well established that graphene, the prototypical 2D electronic material, exhibits novel electronic and optical behavior, yet the intrinsic photoresponse is still under considerable investigation. Recent work has shown that graphene's photoresponse is mediated by hot electronic carriers, which require long time scales to cool, thus resulting in an unusual transport regime. The QMO lab continues to explore various aspects of this transport regime.
Development and design of novel nanospectroscopy techniques
The QMO lab is very active in the area of precision optoelectronic measurements of nanoscale devices and the development of spatially and spectrally resolved optoelectronic techniques. We are currently developing ultrafast optical techniques to probe fundamental electronic behavior of quantum-confined materials such as graphene, hexagonal boron nitride, and the transition metal dichalcogenides.