Advances in computing and energy sciences lie at the core of mankind’s progress towards a sustainable world in the 21st century and beyond. Considering the current state-of-the-art, it is imperative that the key scientific breakthroughs will arise from understanding of charge and energy dynamics at the atomic and molecular length scales. The past three decades have seen tremendous progress in the exploration of nanometer scale materials and their fundamentally unique properties. The challenges of coming decades will involve precise control of their properties and functions when integrated into devices. Our lab will focus on these challenges of integration, assembly and characterization of atomic scale materials into electronic and photonic devices for applications ranging from computing switches to sensors to renewable energy devices such as photovoltaics and light-emitting devices. The group will focus on three major themes described below:
Charge and Exciton Transport across Heterogeneous Interfaces:
Quantum confinement in materials induces fundamental changes in electronics band-structures and the density of states function. Until recently, there were no clear opportunities to make intimate electronic contacts between two structures with different dimensionalities. The advent of stable, free-standing, atomically thin sheets allows interfacing them with other quantum confined materials to create heterogeneous interfaces both in atomic structure and electronic confinement. This opens a new world of possibility for exploring equilibrium charge-transport as well as nature of excited states across such hetero-interfaces. The group will develop schemes to assemble, tune and measure charge transport, energy transfer and excited-state phenomena at the above described hetero-interfaces. The fundamental understanding gained would have widespread implications in low-power switching, optical modulators, quantum-light emission sources as well as photovoltaics.
Engineering Atomic and Electronic Structures in Two-Dimensions:
While the past decade has seen a number of atomically-thin materials emerge with a variety in structure and properties, a majority of the efforts have been focused on stacking disparate materials to make heterostructure devices. However, the same can in principle be achieved in a two-dimensional atomic plane to explore a wide variety of new electrical, optical and quantum phenomena at one and zero dimensional interfaces. The group will develop high temperature growth and synthesis techniques combined with micro and nanofabrication to create quantum confined structures within the two-dimensional atomic plane and explore their properties. The understanding gained would have implications ranging from lasers and quantum light emitters to catalysis and photo-electrochemistry
Integrated Heterostructures for High-Performance Solid-State Devices:
Nanomaterials have provided unique advantages and benefits over bulk materials in solid state devices, however only limited to in lab-scale demonstrations. Integration of low-dimensional nanomaterials with well-known bulk semiconductors via direct growth or post-synthetic transfer therefore provides unique opportunity to make devices with properties and functions not achieved or superior to those achieved by either of them separately. The group will focus on design and fabrication of heterojunction devices combining low-dimensional materials with conventional bulk materials to gain advantages in performance and function.