Wide/Ultrawide Bandgap
Semiconductors Laboratory
Semiconductors Laboratory
Electrical &
Computer Engineering
Texas Tech University
Our laboratory grows, fabricates, and characterizes wide- and ultrawide-bandgap semiconductors — III-nitrides such as GaN, AlN, and AlGaN, and oxides such as β-Ga₂O₃ — and develops them into next-generation photonic and electronic devices. Our core research areas are below.
Light-emitting diodes (LEDs), nanowire LEDs, laser diodes, and single photon sources for quantum photonics.
III-nitride and oxide-based memory devices (RRAM), field-effect transistors (FETs), and HEMTs.
Epitaxial growth, fabrication, and characterization of oxide and nitride semiconductors for solar fuel cells.
We grow high-quality oxide and nitride semiconductor crystals using molecular beam epitaxy (MBE), controlling composition and doping layer by layer. The work spans the full device pipeline — from epitaxial growth, to cleanroom device fabrication, to structural, optical, and electrical characterization — linking material quality to device performance.
Using nanostructures such as nanowires, we engineer light-emitting diodes (LEDs), laser diodes, optical waveguides, and photodetectors across a broad spectral range from the deep ultraviolet to the visible. Nanoscale geometries help relax strain and improve light extraction and carrier confinement, enabling efficient, phosphor-free emitters.
III-nitride micro-LEDs and full-color nanowire emitters are strong candidates for next-generation micro-displays and augmented/virtual reality, where high brightness, efficiency at small pixel sizes, and integration on silicon or flexible substrates are essential. We develop emitter arrays aimed at these high-resolution display platforms.
Ultraviolet-C light (in the roughly 200–280 nm germicidal range) inactivates bacteria and viruses by damaging their genetic material, making compact AlGaN-based UV and far-UVC LEDs attractive for disinfecting surfaces, air, and water. We work to improve the efficiency of these narrow-band UV emitters for practical disinfection applications.
Quantum emitters that release light one photon at a time are fundamental building blocks for quantum communication, computing, and sensing. We investigate nanostructured III-nitride sources, where quantum confinement in nanoscale features can produce single-photon emission, working toward electrically driven quantum-photonic devices.
Beyond light, wide-bandgap materials excel in power and high-frequency electronics. We develop resistive random-access memory (RRAM) based on III-nitrides and β-Ga₂O₃, along with field-effect transistors (FETs) and high-electron-mobility transistors (HEMTs). Their wide bandgaps support high breakdown voltages and reliable operation in high-power, high-temperature, and harsh environments.
III-nitride nanostructures can absorb a wide portion of the solar spectrum, making them promising for both photovoltaics and “solar fuels.” In solar fuel cells, sunlight drives photoelectrochemical reactions — such as splitting water to generate hydrogen or reducing CO₂ — storing solar energy in chemical bonds. We explore InGaN/GaN nanowire architectures for efficient solar cells and solar-to-fuel conversion.