Formation of a Positive Fixed Charge at c-Si(111)/a-Si3N3.5
- Author(s)
- L. E. Hintzsche, C. M. Fang, M. Marsman, M. W. P. E. Lamers, A. W. Weeber, G. Kresse
- Abstract
Modern electronic devices are unthinkable without the well-controlled formation of interfaces at heterostructures. These structures often involve at least one amorphous material. Modeling such interfaces poses a significant challenge, since a meaningful result can be expected only by using huge models or by drawing from many statistically independent samples. Here we report on the results of high-throughput calculations for interfaces between crystalline silicon (c-Si) and amorphous silicon nitride (a-Si3N3.5: H), which are omnipresent in commercially available solar cells. The findings reconcile only partly understood key features. At the interface, threefold-coordinated Si atoms are present. These are caused by the structural mismatch between the amorphous and crystalline parts. The local Fermi level of undoped c-Si lies well below that of a-SiN: H. To align the Fermi levels in the device, charge is transferred from the a-SiN: H part to the c-Si part resulting in an abundance of positively charged, threefold-coordinated Si atoms at the interface. This explains the existence of a positive, fixed charge at the interface that repels holes.
- Organisation(s)
- Computational Materials Physics
- External organisation(s)
- ECN Solar Energy
- Journal
- Physical Review Applied
- Volume
- 3
- No. of pages
- 7
- ISSN
- 2331-7019
- DOI
- https://doi.org/10.1103/PhysRevApplied.3.064005
- Publication date
- 06-2015
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103025 Quantum mechanics, 103036 Theoretical physics, 103015 Condensed matter, 103009 Solid state physics
- Keywords
- ASJC Scopus subject areas
- General Physics and Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/dcad5042-7721-461b-993e-05dd7fdb6f93