Premium
Influence of dopant segregation on the work function and electrical properties of Ge‐doped in comparison to Sn‐doped In 2 O 3 thin films
Author(s) -
Hoyer Karoline L.,
Hubmann Andreas H.,
Klein Andreas
Publication year - 2017
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201600486
Subject(s) - dopant , materials science , doping , x ray photoelectron spectroscopy , oxidizing agent , sputter deposition , work function , thin film , grain boundary , electron mobility , analytical chemistry (journal) , sputtering , chemical engineering , metal , metallurgy , optoelectronics , nanotechnology , chemistry , microstructure , organic chemistry , chromatography , engineering
Ge‐doped In 2 O 3 thin films prepared by magnetron sputtering are studied using photoelectron spectroscopy and Hall effect measurements. Carrier conductivities of up to 8.35 ×10 3 cm − 1and carrier mobilities of up to 57cm 2V − 1s − 1are observed. The surface Ge concentration is enhanced by a factor of 2–3 compared to the concentration in the interior of the films. The surface Ge concentration increases with more oxidizing deposition conditions, in opposite to what has been reported for Sn‐doped In 2 O 3 . Ge‐doped In 2 O 3 films exhibit higher work functions as compared to Sn‐doped films, in particular at oxidizing conditions. This is attributed to the formation of a GeO 2 surface phase. While segregation of Sn reduces the carrier mobility due to grain boundary scattering, Ge segregation does not show such an effect. The differences are attributed to the different oxidation states of the segregated dopants, in agreement with the observed dependence of segregation on oxygen activity.