Formation of a Positive Fixed Charge at c-Si(111)/a-Si3N3.5

Autor(en)

L. E. Hintzsche, C. M. Fang, M. Marsman, M. W. P. E. Lamers, A. W. Weeber, G. Kresse

Abstrakt

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(en)

Computergestützte Materialphysik

Externe Organisation(en)

Energy Research Centre of the Netherlands

Journal

Physical Review Applied

Band

3

Anzahl der Seiten

7

ISSN

2331-7019

DOI

https://doi.org/10.1103/PhysRevApplied.3.064005

Publikationsdatum

06-2015

Peer-reviewed

Ja

ÖFOS 2012

103025 Quantenmechanik, 103036 Theoretische Physik, 103015 Kondensierte Materie, 103009 Festkörperphysik

Schlagwörter

ASJC Scopus Sachgebiete

Allgemeine Physik und Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/dcad5042-7721-461b-993e-05dd7fdb6f93