Enrique studies the effects of defects in materials using computational methods. Methods range from classical Metropolis Monte Carlo, density functional (DFT), and many-body perturbation GW plus Bethe-Salpeter equation.
Computational studies of Amorphous Silicon (a-Si):
a-Si is a semiconductor with randomness built-in to the atomic coordinates. This material (especially when paired with crystalline Si (c-Si) in the Heterojunction with Intrinsic Thin-layer cell) is a useful photovoltaic that can be used as the active component in solar cells. The randomness in a-Si brings its own set of challenges when studying the material, the primary of which is that relative atomic coordinates are unknown, in contrast to a crystal.
Enrique is a developer of the Monte Carlo Code CHASSM which uses the classical Wooten-Winer-Weaire method to generate randomized but physically realistic coordinates of a-Si. These structures are further studied using other ab initio methods to study the effects of voids, dangling bonds, Hydrogen, and amorphous-to-crystal interfaces.
Computational studies of Molybdenum Disulphide (MoS2):
MoS2 is a semiconducting transition metal dichalcogenide with many interesting properties owed to its layered structure. Two applications of particular interest are catalysis and solid lubrication and its catalyzing and lubricating abilities are enhanced by introducing defects such as Ni, though clear explanations as to why are often lacking. Enrique uses DFT and density functional perturbation theory to study the effects of defects on MoS2. These effects can be used to compare to experiment and may shed light as to the specifics of how these defects enhance MoS2 properties.
R. Karkee, E. Guerrero, D. A. Strubbe, "Structural/phase changes and enhanced interlayer interactions in Ni-doped MoS2 from density functional theory" arXiv:2008.04301, 2020
Enrique Guerrero, Rijan Karkee, and David A. Strubbe. "Phase Stability and Raman/IR Signatures of Ni-Doped MoS2 from Density-Functional Theory Studies." arXiv:2010.02198 (2021)
Enrique Guerrero and David A. Strubbe. "Computational generation of voids in a-Si and a-Si:H by cavitation at low density" Phys. Rev Materials 4 025601 (2020)
PhD Physics - University of California, Merced - expected 2021
M.S. Physics - University of California, Merced - 2019
B.S. Physics - Humboldt State University - 2015