Exploring the effects of bismuth clustering on the energy band gap of GaBixAs1-x semiconductors
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.
This project is funded by the National Science Foundation under DMR - 1505628.- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..MARB67009C