In this study, we report that the carrier mobility of 2%-La-doped BaSnO3 (LBSO) films on (001) SrTiO3 and (001) MgO substrates strongly depends on the thickness, whereas it is unrelated to the film/substrate lattice mismatch (+5.4% for SrTiO3 and −2.3% for MgO). The films exhibited large differences in lattice parameters, lateral grain sizes (∼85 nm for SrTiO3 and ∼20 nm for MgO), surface morphologies, threading dislocation densities, and misfit dislocation densities. However, the mobility dependences on the film thickness in both cases were almost the same, saturating at ∼100 cm2 V−1 s−1, while the charge carrier densities approached the nominal carrier concentration (=[2% La3+]). Our study clearly indicates that the carrier mobility of LBSO films strongly depends on the thickness. These results would be beneficial for understanding the carrier transport properties and fruitful to further enhance the mobility of LBSO films.
References
1.
D. S.
Ginley
, H.
Hosono
, and D. C.
Paine
, Handbook of Transparent Conductors
(Springer
, New York
, 2010
).2.
P.
Barquinha
, R.
Martins
, L.
Pereira
, and E.
Fortunato
, Transparent Oxide Electronics: From Materials to Devices
(Wiley
, West Sussex
, 2012
).3.
H. J.
Kim
, U.
Kim
, H. M.
Kim
, T. H.
Kim
, H. S.
Mun
, B.-G.
Jeon
, K. T.
Hong
, W.-J.
Lee
, C.
Ju
, K. H.
Kim
, and K.
Char
, “High mobility in a stable transparent perovskite oxide
,” Appl. Phys. Express
5
, 061102
(2012
).4.
H. J.
Kim
, U.
Kim
, T. H.
Kim
, J.
Kim
, H. M.
Kim
, B.-G.
Jeon
, W.-J.
Lee
, H. S.
Mun
, K. T.
Hong
, J.
Yu
, K.
Char
, and K. H.
Kim
, “Physical properties of transparent perovskite oxides (Ba,La)SnO3 with high electrical mobility at room temperature
,” Phys. Rev. B
86
, 165205
(2012
).5.
A. V.
Sanchela
, T.
Onozato
, B.
Feng
, Y.
Ikuhara
, and H.
Ohta
, “Thermopower modulation clarification of the intrinsic effective mass in transparent oxide semiconductor BaSnO3
,” Phys. Rev. Mater.
1
, 034603
(2017
).6.
K.
Krishnaswamy
, B.
Himmetoglu
, Y.
Kang
, A.
Janotti
, and C. G.
Van de Walle
, “First-principles analysis of electron transport in BaSnO3
,” Phys. Rev. B
95
, 205202
(2017
).7.
H.
Paik
, Z.
Chen
, E.
Lochocki
, A.
Seidner H
, A.
Verma
, N.
Tanen
, J.
Park
, M.
Uchida
, S.
Shang
, B.-C.
Zhou
, M.
Brützam
, R.
Uecker
, Z.-K.
Liu
, D.
Jena
, K. M.
Shen
, D. A.
Muller
, and D. G.
Schlom
, “Adsorption-controlled growth of La-doped BaSnO3 bymolecular-beam epitaxy
,” APL Mater.
5
, 116107
(2017
).8.
S.
Raghavan
, T.
Schumann
, H.
Kim
, J. Y.
Zhang
, T. A.
Cain
, and S.
Stemmer
, “High-mobility BaSnO3 grown by oxide molecular beam epitaxy
,” APL Mater.
4
, 016106
(2016
).9.
Z.
Lebens-Higgins
, D. O.
Scanlon
, H.
Paik
, S.
Sallis
, Y.
Nie
, M.
Uchida
, N. F.
Quackenbush
, M. J.
Wahila
, G. E.
Sterbinsky
, D. A.
Arena
, J. C.
Woicik
, D. G.
Schlom
, and L. F.
Piper
, “Direct observation of electrostatically driven band gap renormalization in a degenerate perovskite transparent conducting oxide
,” Phys. Rev. Lett.
116
, 027602
(2016
).10.
P. V.
Wadekar
, J.
Alaria
, M.
O'Sullivan
, N. L. O.
Flack
, T. D.
Manning
, L. J.
Phillips
, K.
Durose
, O.
Lozano
, S.
Lucas
, J. B.
Claridge
, and M. J.
Rosseinsky
, “Improved electrical mobility in highly epitaxial La:BaSnO3 films on SmScO3 (110) substrates
,” Appl. Phys. Lett.
105
, 052104
(2014
).11.
C. A.
Niedermeier
, S.
Rhode
, S.
Fearn
, K.
Ide
, M. A.
Moram
, H.
Hiramatsu
, H.
Hosono
, and T.
Kamiya
, “Solid phase epitaxial growth of high mobility La:BaSnO3 thin films co-doped with interstitial hydrogen
,” Appl. Phys. Lett.
108
, 172101
(2016
).12.
K.
Ganguly
, P.
Ambwani
, P.
Xu
, J. S.
Jeong
, K. A.
Mkhoyan
, C.
Leighton
, and B.
Jalan
, “Structure and transport in high pressure oxygen sputter-deposited BaSnO3−δ
,” APL Mater.
3
, 062509
(2015
).13.
H.
Mun
, U.
Kim
, H.
Min Kim
, C.
Park
, T.
Hoon Kim
, H.
Joon Kim
, K.
Hoon Kim
, and K.
Char
, “Large effects of dislocations on high mobility of epitaxial perovskite Ba0.96La0.04SnO3 films
,” Appl. Phys. Lett.
102
, 252105
(2013
).14.
U.
Kim
, C.
Park
, T.
Ha
, R.
Kim
, H. S.
Mun
, H. M.
Kim
, H. J.
Kim
, T. H.
Kim
, N.
Kim
, J.
Yu
, K. H.
Kim
, J. H.
Kim
, and K.
Char
, “Dopant-site-dependent scattering by dislocations in epitaxial films of perovskite semiconductor BaSnO3
,” APL Mater.
2
, 056107
(2014
).15.
J.
Shiogai
, K.
Nishihara
, K.
Sato
, and A.
Tsukazaki
, “Improvement of electron mobilityin La:BaSnO3 thin films by insertion of an atomically flat insulating (Sr,Ba)SnO3 buffer layer
,” AIP Adv.
6
, 065305
(2016
).16.
W.-J.
Lee
, H. J.
Kim
, E.
Sohn
, T. H.
Kim
, J.-Y.
Park
, W.
Park
, H.
Jeong
, T.
Lee
, J. H.
Kim
, K.-Y.
Choi
, and K. H.
Kim
, “Enhanced electron mobility in epitaxial (Ba, La)SnO3films on BaSnO3 (001) substrates
,” Appl. Phys. Lett.
108
, 082105
(2016
).17.
J.
Shin
, Y. M.
Kim
, Y.
Kim
, C.
Park
, and K.
Char
, “High mobility BaSnO3 films and field effect transistors on non-perovskite MgO substrate
,” Appl. Phys. Lett.
109
, 262102
(2016
).18.
C.
Park
, U.
Kim
, C. J.
Ju
, J. S.
Park
, Y. M.
Kim
, and K.
Char
, “High mobility field effect transistor based on BaSnO3 with Al2O3 gate oxide
,” Appl. Phys. Lett.
105
, 203503
(2014
).19.
W. Y.
Wang
, Y. L.
Tang
, Y. L.
Zhu
, J.
Suriya prakash
, Y. B.
Xu
, Y.
Liu
, B.
Gao
, S. W.
Cheong
, and X. L.
Ma
, “Atomic mapping of Ruddlesden-Popper faults in transparent conducting BaSnO3-based thin films
,” Sci. Rep.
5
, 16097
(2015
).20.
A.
Prakash
, P.
Xu
, A.
Faghaninia
, S.
Shukla
, J. W.
Ager
, C. S.
Lo
, and B.
Jalan
, “Wide band gap BaSnO3 films with room temperature conductivity exceeding 104 S cm−1
,” Nat. Commun.
8
, 15167
(2017
).21.
A.
Prakash
, P.
Xu
, X.
Wu
, G.
Haugstad
, X.
Wang
, and B.
Jalan
, “Adsorption-controlled growth and the influence of stoichiometry on electronic transport in hybrid molecular beam epitaxy-grown BaSnO3 films
,” J. Mater. Chem. C
5
, 5730
(2017
).22.
Y.
Ozaki
, D.
Kan
, and Y.
Shimakawa
, “Influence of cation off-stoichiometry on structural and transport properties of (Ba, La)SnO3 epitaxial thin films grown by pulsed laser deposition
,” J. Appl. Phys.
121
, 215304
(2017
).23.
W.-J.
Lee
, H. J.
Kim
, J.
Kang
, D. H.
Jang
, T. H.
Kim
, J. H.
Lee
, and K. H.
Kim
, “Transparent perovskite barium stannate with high electron mobility and thermal stability
,” Annu. Rev. Mater. Res.
47
, 391
(2017
).24.
© 2018 Author(s).
2018
Author(s)
You do not currently have access to this content.
