Evidence for indirect band gap in BaSnO3 using angle-resolved photoemission spectroscopy

다국어 초록 (Multilingual Abstract)

Transparent BaSnO3 thin films have been proposed as an alternative transparent conducting oxide (TCO). Although bulk synthesis and high-quality fabrication of epitaxial films are well established, there are still unsolved aspects about their electronic structure, such as the direct or indirect nature and the size of the band gap. We investigated the electronic structure of epitaxial BaSnO3 thin films using in situ angleresolved photoemission spectroscopy. We directly measured an indirect band gap of 3.7 eV, a value compatible with those of previous reports, but we also identified additional in-gap states at 1.6 eV below the conduction band minimum that we attribute to intrinsic defects, mainly oxygen vacancies.

참고문헌 (Reference)

1 J. Rho, "Unconventional photoluminescence effect of SrTiO3 thin film under UV-illumination" 131 : 1813-1816, 2011

2 S. Moser, "Tunable polaronic conduction in anatase TiO2" 110 : 196403-, 2013

3 T. Minami, "Transparent conducting oxide semiconductors for transparent electrodes" 20 : 35-44, 2005

4 H. C. Kim, "Transparent conducting aluminum-doped zinc oxide thin films for organic light-emitting devices" 76 : 259-261, 2000

5 S. Suwanwong, "The dynamics of ultraviolet-induced oxygen vacancy at the surface of insulating SrTiO3(001)" 355 : 210-212, 2015

6 장영준, "Temperature-dependent Electronic Structure Change in Semiconducting BaTiO₃" 한국물리학회 64 (64): 15-18, 2014

7 S. Lany, "Surface Origin of High Conductivities in Undoped In2O3" 16802 : 2-6, 2012

8 E. Moreira, "Structural and electronic properties of SrxBa1-xSnO3 from first principles calculations" 187 : 186-194, 2012

9 D. J. Singh, "Strain effects on the band gap and optical properties of perovskite SrSnO3 and BaSnO3" 104 : 11910-, 2014

10 Miru Noh, "Spectroscopic ellipsometry investigation on the excimer laser annealed indium thin oxide solegel films" 한국물리학회 16 (16): 145-149, 2016

11 Q. Liu, "Room-temperature ferromagnetism in transparent Mn-doped BaSnO3 epitaxial films" 7 : 33006-, 2014

12 H. Mizoguchi, "Probing the electronic structures of ternary perovskite and pyrochlore oxides containing Sn4+ or Sb5+" 43 : 1667-1680, 2004

13 H. J. Kim, "Physical properties of transparent perovskite oxides (Ba,La)SnO3 with high electrical mobility at room temperature" 86 : 165205-, 2012

14 H. R. Liu, "Origin of the superior conductivity of perovskite Ba(Sr)SnO3" 102 : 112109-, 2013

15 S. M. Xing, "Optoelectronic properties and interband transition of La-doped BaSnO3 transparent conducting films determined by variable temperature spectral transmittance" 117 : 103107-, 2015

16 C. Shan, "Optical and electrical properties of solegel derived Ba1e xLaxSnO3 transparent conducting films for potential optoelectronic applications" 118 : 6994-7001, 2014

17 K. H. L. Zhang, "Microscopic origin of electron accumulation in In2O3" 56803 : 1-5, 2013

18 G. Thomas, "Materials science: invisible circuits" 389 : 907-908, 1997

19 Y. S. Kim, "Localized electronic states induced by defects and possible origin of ferroelectricity in strontium titanate thin films" 94 : 202906-, 2009

20 K. Hayashi, "Light-induced conversion of an insulating refractory oxide into a persistent electronic conductor" 419 : 462-465, 2002

21 Y. J. Chang, "Layer-by-layer evolution of a twodimensional electron gas near an oxide interface" 111 : 126401-, 2013

22 S. Sallis, "La-doped BaSnO3 - degenerate perovskite transparent conducting oxide: evidence from synchrotron x-ray spectroscopy" 103 : 42105-, 2013

23 D. Seo, "Infrared-optical spectroscopy of transparent conducting perovskite (La,Ba)SnO3 thin films" 104 : 22102-, 2014

24 Dongmin Seo, "Infrared Conductivity of PED-grown (La,Ba)SnO3 Thin Films" 한국물리학회 64 (64): 764-767, 2014

25 B. G. Kim, "Hybrid functional calculation of electronic and phonon structure of BaSnO3" 197 : 134-138, 2013

26 H. J. Kim, "High mobility in a stable transparent perovskite oxide" 5 : 61102-, 2012

27 C. Park, "High mobility field effect transistor based on BaSnO3 with Al2O3 gate oxide" 105 : 203503-, 2014

28 Q. Liu, "High electrical conductivity in oxygen deficient BaSnO3 films" 655 : 389-394, 2016

29 Jaehong Yoon, "High efficiency AZO-InP nanopillar-based heterojunction solar cells" 한국물리학회 16 (16): 726-730, 2016

30 X. Luo, "High carrier mobility in transparent Ba1 xLaxSnO3 crystals with a wide band gap" 100 : 172112-, 2012

31 J. H. Lee, "Freeland, Dynamic layer rearrangement during growth of layered oxide films by molecular beam epitaxy" 13 : 879-883, 2014

32 C. Janowitz, "Experimental electronic structure of In2O3 and Ga2O3" 13 : 85014-, 2011

33 T. N. Stanislavchuk, "Electronic band structure and optical phonons of BaSnO3 and Ba0.97La0.03SnO3single crystals: theory and experiment" 112 : 44108-, 2012

34 T. Wolfram, "Electronic and Optical Properties of d-band Perovskites" Cambridge University Press 2006

35 Min-Seung Choi, "Effects of hydrogen plasma treatment on SnO2:F substrates for amorphous Si thin film solar cells" 한국물리학회 13 (13): 1589-1593, 2013

36 D. G. Lee, "Effective passivation of Ag nanowirebased flexible transparent conducting electrode by TiO2 nanoshell" 3 : 20-, 2016

37 Y. Zhang, "Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2" 9 : 111-115, 2014

38 Z. Lebens-Higgins, "Direct observation of electrostatically driven band gap renormalization in a degenerate perovskite transparent conducting oxide" 116 : 27602-, 2016

39 B.C. Luo, "Determination of the effective mass and nanoscale electrical transport in La-doped BaSnO3 thin films" 한국물리학회 16 (16): 20-23, 2016

40 D.O. Scanlon, "Defect engineering of BaSnO3 for high-performance transparent conducting oxide applications" 87 : 161201-, 2013

41 Q. Liu, "Composition dependent metal-semiconductor transition in transparent and conductive Ladoped BaSnO3 epitaxial films" 101 : 241901-, 2012

42 이보화, "Coherent Growth Behavior of an Orthorhombic (Ca,Sr)SnO3 Thin Film on a Cubic SrTiO3 (110) Substrate" 한국물리학회 61 (61): 795-798, 2012

43 R. Chen, "Co-percolating graphene-wrapped silver nanowire network for high performance, highly stable, transparent conducting electrodes" 23 : 5150-5158, 2013

44 S. H. Cho, "Chemical and biological sensors based on defect-engineered graphene mesh field-effect transistors" 3 : 14-, 2016

45 S. H. Chae, "Carbon nanotubes and graphene towards soft electronics" 1 : 15-, 2014

46 송나영, "BaSnO3에서의 여러 Hybrid functional 을 이용한 전자구조 비교 계산" 한국물리학회 64 (64): 760-766, 2014

47 L. Y. Lim, "Angleresolved photoemission and quasiparticle calculation of ZnO: the need for d band shift in oxide semiconductors" 86 : 1-6, 2012