Exploring the effects of bismuth clustering on the energy band gap of GaBixAs1-x semiconductors
ORAL
Abstract
Substituting Bi anions in place of As allows for effective tuning of the energy band gap
of GaBixAs1-x. Such band gap control has applications in spintronics (quantum
computing) and optoelectronics (photovoltaics). The energy band gap of dilute GaBixAs1-x alloys is dependent on the alloy configuration, in addition to the alloy concentration. In
order to explore the effects of Bi configuration in dilute GaBixAs1-x alloys, an atomistic,
nearest-neighbor, sp3s* tight-binding Hamiltonian is used to determine the
energy levels for statistically constructed alloy supercells with random, clustered,
and gaussian weighted distributions . By correlating these energies to both qualitative
and quantitative measures of Bi clustering, the effects of Bi clustering are explored.
From our theoretical calculations, we show that increases in Bi clustering correlate with
greater decrease in band gap energies. Additionally, in more densely clustered
configurations, we see higher total Bi probability for hole states and faster Bi band
broadening congruent with the band anti-crossing model for GaBixAs1-x.
of GaBixAs1-x. Such band gap control has applications in spintronics (quantum
computing) and optoelectronics (photovoltaics). The energy band gap of dilute GaBixAs1-x alloys is dependent on the alloy configuration, in addition to the alloy concentration. In
order to explore the effects of Bi configuration in dilute GaBixAs1-x alloys, an atomistic,
nearest-neighbor, sp3s* tight-binding Hamiltonian is used to determine the
energy levels for statistically constructed alloy supercells with random, clustered,
and gaussian weighted distributions . By correlating these energies to both qualitative
and quantitative measures of Bi clustering, the effects of Bi clustering are explored.
From our theoretical calculations, we show that increases in Bi clustering correlate with
greater decrease in band gap energies. Additionally, in more densely clustered
configurations, we see higher total Bi probability for hole states and faster Bi band
broadening congruent with the band anti-crossing model for GaBixAs1-x.
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Presenters
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John Carlton
University of Maryland, College Park, JQI, NIST
Authors
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John Carlton
University of Maryland, College Park, JQI, NIST
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Arthur Lin
Physics, University of Maryland, Joint Quantum Institute, University of Maryland and NIST, University of Maryland, College Park, JQI, NIST
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Garnett Bryant
National Institute of Standards and Technology, University of Maryland, College Park, JQI, NIST, Atomic-Scale Device Group, NIST, NIST