# Selected Publications

### Interlayer resistance of misoriented MoS2

Interlayer misorientation in transition metal dichalcogenides alters their interlayer distance, total energy, electronic band structure, and vibrational modes, but its effect on the interlayer resistance is not known. This study analyzes the interlayer resistance of misoriented bilayer MoS2 as a function of the misorientation angle, and it shows that interlayer misorientation exponentially increases the electron resistivity while leaving the hole resistivity almost unchanged. The physics, determined by the wave functions at the high symmetry points, are generic among the popular semiconducting transition metal dichalcogenides (TMDs). The asymmetrical effect of misorientation on the electron and hole transport may be exploited in the design and optimization of vertical transport devices such as a bipolar transistor. Density functional theory provides the interlayer coupling elements used for the resistivity calculations.
PCCP, RSC

# Presentations

• S. Su, P. Das, K. Zhou, A. Zahin, S. Ge, S. S. Sylvia, B. Debnath, R. Lake, Electronic, Thermoelectric, and Vibrational Properties of Few-layer van der Waals Materials for Device Applications, FAME Annual review, UCLA, Feb. 2017.
• K. Zhou, D. Wickramaratne, S. Ge, and R. Lake, Transport Properties Across Misoriented Bilayer MoS2 Using ab initio Calculations and Non-Equilibrium Green Functions, MRS Spring meeting, Phoenix, AZ, April 2016.
• K. Zhou, D. Wickramaratne, S. Ge, and R. Lake, The Interlayer Resistance of a Misoriented Bilayer MoS2 Interface, APS March Meeting, Baltimore, MD, March 2016.
• K. Zhou, D. Wickramaratne, and R. Lake, Transport Properties Across Misoriented Bilayer MoS2 using Ab-initio Calculations, APS March meeting, San Antonio, TX, March 2015.

# Projects

• Tasked with providing electronic band structures, Landau level energies, and resistivity for tetralayer graphene using the electronic structure calculated from a tight-binding model as input into the Boltzmann transport equation within a relaxation time approximation.

• Found that the electron and hole resistivities differed by several orders of magnitude depending on the rotation angle, and how this property could be exploited in the design of a high-frequency bipolar junction transistor or heterostructure bipolar transistor.

• Benchmarked the performance of OpenMX to calculate electron transport for several systems with large computing requirement.

• Developed quantum control techniques in NMR systems, including optimization of the Gradient Ascent Pulse Engineering algorithm (GRAPE).

# Skills

C, C++, Python, Matlab, Mathematica, VASP, Quantum ESPRESSO, OpenMX, Linux, High performance computing, Latex, Adobe Photoshop