skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on November 13, 2018

Title: Effects of the c-Si/a-SiO 2 interfacial atomic structure on its band alignment: an ab initio study

The crystalline-Si/amorphous-SiO 2 (c-Si/a-SiO 2) interface is an important system used in many applications, ranging from transistors to solar cells. The transition region of the c-Si/a-SiO 2 interface plays a critical role in determining the band alignment between the two regions. However, the question of how this interface band offset is affected by the transition region thickness and its local atomic arrangement is yet to be fully investigated. Here in this study, by controlling the parameters of the classical Monte Carlo bond switching algorithm, we have generated the atomic structures of the interfaces with various thicknesses, as well as containing Si at different oxidation states. A hybrid functional method, as shown by our calculations to reproduce the GW and experimental results for bulk Si and SiO 2, was used to calculate the electronic structure of the heterojunction. This allowed us to study the correlation between the interface band characterization and its atomic structures. We found that although the systems with different thicknesses showed quite different atomic structures near the transition region, the calculated band offset tended to be the same, unaffected by the details of the interfacial structure. Our band offset calculation agrees well with the experimental measurements. This robustnessmore » of the interfacial electronic structure to its interfacial atomic details could be another reason for the success of the c-Si/a-SiO 2 interface in Si-based electronic applications. Nevertheless, when a reactive force field is used to generate the a-SiO 2 and c-Si/a-SiO 2 interfaces, the band offset significantly deviates from the experimental values by about 1 eV« less
Authors:
ORCiD logo [1] ;  [2] ;  [2]
  1. Joint Center for Artificial Photosynthesis and Materials Sciences Division; Lawrence Berkeley National Laboratory; Berkeley; USA
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Joint Center for Artificial Photosynthesis and Materials Sciences Division
Publication Date:
Grant/Contract Number:
AC02-05CH11231; SC0004993
Type:
Accepted Manuscript
Journal Name:
Physical Chemistry Chemical Physics. PCCP (Print)
Additional Journal Information:
Journal Name: Physical Chemistry Chemical Physics. PCCP (Print); Journal Volume: 19; Journal Issue: 48; Journal ID: ISSN 1463-9076
Publisher:
Royal Society of Chemistry
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 14 SOLAR ENERGY
OSTI Identifier:
1418293

Zheng, Fan, Pham, Hieu H., and Wang, Lin-Wang. Effects of the c-Si/a-SiO2 interfacial atomic structure on its band alignment: an ab initio study. United States: N. p., Web. doi:10.1039/c7cp05879a.
Zheng, Fan, Pham, Hieu H., & Wang, Lin-Wang. Effects of the c-Si/a-SiO2 interfacial atomic structure on its band alignment: an ab initio study. United States. doi:10.1039/c7cp05879a.
Zheng, Fan, Pham, Hieu H., and Wang, Lin-Wang. 2017. "Effects of the c-Si/a-SiO2 interfacial atomic structure on its band alignment: an ab initio study". United States. doi:10.1039/c7cp05879a.
@article{osti_1418293,
title = {Effects of the c-Si/a-SiO2 interfacial atomic structure on its band alignment: an ab initio study},
author = {Zheng, Fan and Pham, Hieu H. and Wang, Lin-Wang},
abstractNote = {The crystalline-Si/amorphous-SiO2 (c-Si/a-SiO2) interface is an important system used in many applications, ranging from transistors to solar cells. The transition region of the c-Si/a-SiO2 interface plays a critical role in determining the band alignment between the two regions. However, the question of how this interface band offset is affected by the transition region thickness and its local atomic arrangement is yet to be fully investigated. Here in this study, by controlling the parameters of the classical Monte Carlo bond switching algorithm, we have generated the atomic structures of the interfaces with various thicknesses, as well as containing Si at different oxidation states. A hybrid functional method, as shown by our calculations to reproduce the GW and experimental results for bulk Si and SiO2, was used to calculate the electronic structure of the heterojunction. This allowed us to study the correlation between the interface band characterization and its atomic structures. We found that although the systems with different thicknesses showed quite different atomic structures near the transition region, the calculated band offset tended to be the same, unaffected by the details of the interfacial structure. Our band offset calculation agrees well with the experimental measurements. This robustness of the interfacial electronic structure to its interfacial atomic details could be another reason for the success of the c-Si/a-SiO2 interface in Si-based electronic applications. Nevertheless, when a reactive force field is used to generate the a-SiO2 and c-Si/a-SiO2 interfaces, the band offset significantly deviates from the experimental values by about 1 eV},
doi = {10.1039/c7cp05879a},
journal = {Physical Chemistry Chemical Physics. PCCP (Print)},
number = 48,
volume = 19,
place = {United States},
year = {2017},
month = {11}
}

Works referenced in this record:

Generalized Gradient Approximation Made Simple
journal, October 1996
  • Perdew, John P.; Burke, Kieron; Ernzerhof, Matthias
  • Physical Review Letters, Vol. 77, Issue 18, p. 3865-3868
  • DOI: 10.1103/PhysRevLett.77.3865