Aaron R Altman
Ph.D. Student in Materials Science and Engineering, admitted Summer 2021
All Publications
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Identifying Hidden Intracell Symmetries in Molecular Crystals and Their Impact for Multiexciton Generation.
The journal of physical chemistry letters
1800: 747-753
Abstract
Organic molecular crystals are appealing for next-generation optoelectronic applications due to their multiexciton generation processes that can increase the efficiency of photovoltaic devices. However, a general understanding of how crystal structures affect these processes is lacking, requiring computationally demanding calculations for each material. Here we present an approach to understand and classify organic crystals and elucidate multiexciton processes. We show that organic crystals that are composed of two sublattices are well-approximated by effective fictitious systems of higher translational symmetry. Within this framework, we derive hidden selection rules in crystal pentacene and predict that the bulk polymorph supports fast Coulomb-mediated singlet fission with a transition rate about 2 orders of magnitude faster than that of the thin-film polymorph, a result confirmed with many-body perturbation theory calculations. Our approach is based on density-functional theory calculations and provides design principles for the experimental and computational discovery of new materials with tailored excitonic properties.
View details for DOI 10.1021/acs.jpclett.1c03540
View details for PubMedID 35029407
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Charge-spin interconversion in epitaxial Pt probed by spin-orbit torques in a magnetic insulator
PHYSICAL REVIEW MATERIALS
2021; 5 (6)
View details for DOI 10.1103/PhysRevMaterials.5.064404
View details for Web of Science ID 000661932200002
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The role of iron in magnetic damping of Mg(Al,Fe)(2)O-4 spinel ferrite thin films
APPLIED PHYSICS LETTERS
2020; 116 (14)
View details for DOI 10.1063/5.0003628
View details for Web of Science ID 000526869500001
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Ultrathin interfacial layer with suppressed room temperature magnetization in magnesium aluminum ferrite thin films
APPLIED PHYSICS LETTERS
2019; 115 (13)
View details for DOI 10.1063/1.5111326
View details for Web of Science ID 000487997400005