Active Research Projects:

Materials Research

• Far from equilibrium semiconductor materials: B-III-V, Tl-III-V, III-V-Bi, and SiGeSn
• Novel materials systems: e.g. IV-VI
• Effects of surfactants and interfactants on epitaxial growth
• Heterogeneous integration of group-IV (C, Si, Ge, and Sn) with III-V materials
• Exploration of the fundamental epitaxial process through machine learning combined with multiscale modeling and in operando sensing
• Phonon scattering reduction in infrared materials
• Auger recombination reduction in infrared materials
• Epitaxial semiconductor-semimetal junction
• Heterogeneous integration of group-IV  (C, Si, Ge, and Sn) with III-V materials
• Earth-abundant simultaneous transparent conducting oxide and anti-reflective coating materials
• Transparent semiconductors for the mid to far infrared
• Optical properties of refractory metals
• Optical properties of semiconductors in the infrared

Photovoltaics (PVs)

• Monolithic multi-lattice multijunction ultra-efficient concentrating PV solar cells
• Novel small band-gap sub-cell materials for multijunction cells
• Earth-abundant simultaneous transparent conducting oxide and anti-reflective coating materials
• Earth-abundant PV materials
• Split junction concentrating photovoltaics.

Thermophotovoltaics (TPVs)

• Extended wavelength (2-10 micron) TPV cells
• Nano-structure enhanced performance TPV cells
• High temperature nanostructured emitters, see below
• Infrared rectennas for thermal energy harvesting

Metamaterials (MMs)

• High temperature selective thermal emitters for TPV cells
• Long wavelength selective thermal emitters for TPV cells
• Static and dynamic polarizers for photodetctor applications
• Photonic Crystal Filters for TPV and photodetector applications
• Fabry-Perot emitters

Photodetectors

• Type-II strained-layer superlattices (SLS) IR photodetectors
• Quantum dots in a well (DWELL) IR photodetectors
• Low-noise, multi-spectral, tunable, detectors for IR astronomy

High-Speed Devices

• Terahertz transistors
• High-speed, low-voltage, semimetal-semiconductor rectifying diodes
• Novel strain-free gate/channel materials for high-speed (500+ GHz) DHBTs and FETs

Past Research Projects:

• Germanium quantum-dot quantum cellular automata (QCA)
• Silicon-Germanium quantum dot superlattices
• Sb-based type-II DHBT high-speed transistors