Research Projects

Mid-infrared (IR) and long-wave-IR photodetectors are essential for various applications, including biomedical imaging, chemical sensing, high-speed optical communication, and thermal imaging. However, their performance is limited by their large energy bandgap, low room temperature sensitivity, and low detection speed. Two-dimensional (2D) semiconductor materials have proven helpful for high-performance, broadband photodetector designs due to their distinctive properties. Their van der Waals (vdWs) heterostructures show distinct band alignments, making them effective for high-speed, low-noise photodetector designs. However, 2D material-based mid and long-wave-IR photodetectors are not well studied due to the unavailability of narrow bandgap 2D materials. This proposed research will investigate novel 2D materials with narrow bandgap energy, such as narrow bandgap TMDs, Type-II Weyl semimetals, and 2D tellurium, using density-functional theory (DFT) based on first-principle calculations. The structural, optical, and electronic properties of these materials will be examined rigorously, and transport through these structures will be studied using non-equilibrium Green's function (NEGF) formalism. Room-temperature photodetectors for mid-infrared and long-wave-infrared wavelengths will be designed using material and device co-optimization techniques, aiming for ultra-high-performance, room-temperature detectability, and integrability with standard CMOs technology.