Back to Search Start Over

Transport Properties and Finite Size Effects in β-Ga 2 O 3 Thin Films.

Authors :
Ahrling R
Boy J
Handwerg M
Chiatti O
Mitdank R
Wagner G
Galazka Z
Fischer SF
Source :
Scientific reports [Sci Rep] 2019 Sep 11; Vol. 9 (1), pp. 13149. Date of Electronic Publication: 2019 Sep 11.
Publication Year :
2019

Abstract

Thin films of the wide band gap semiconductor β-Ga <subscript>2</subscript> O <subscript>3</subscript> have a high potential for applications in transparent electronics and high power devices. However, the role of interfaces remains to be explored. Here, we report on fundamental limits of transport properties in thin films. The conductivities, Hall densities and mobilities in thin homoepitaxially MOVPE grown (100)-orientated β-Ga <subscript>2</subscript> O <subscript>3</subscript> films were measured as a function of temperature and film thickness. At room temperature, the electron mobilities ((115 ± 10) cm <superscript>2</superscript> /Vs) in thicker films (>150 nm) are comparable to the best of bulk. However, the mobility is strongly reduced by more than two orders of magnitude with decreasing film thickness ((5.5 ± 0.5) cm <superscript>2</superscript> /Vs for a 28 nm thin film). We find that the commonly applied classical Fuchs-Sondheimer model does not explain sufficiently the contribution of electron scattering at the film surfaces. Instead, by applying an electron wave model by Bergmann, a contribution to the mobility suppression due to the large de Broglie wavelength in β-Ga <subscript>2</subscript> O <subscript>3</subscript> is proposed as a limiting quantum mechanical size effect.

Details

Language :
English
ISSN :
2045-2322
Volume :
9
Issue :
1
Database :
MEDLINE
Journal :
Scientific reports
Publication Type :
Academic Journal
Accession number :
31511538
Full Text :
https://doi.org/10.1038/s41598-019-49238-2