Effects of multiple heat treatment cycles on structure, optical and electrical properties of indium-tin-oxide thin films

被引:15
作者
Guai, G. H. [1 ]
Song, Q. L. [1 ]
Lu, Z. S. [1 ]
Li, Chang-Ming [1 ]
机构
[1] Nanyang Technol Univ, Sch Chem & Biomed Engn, Ctr Adv Bionanosyst, Singapore 637457, Singapore
关键词
Indium-tin-oxide; Multiple heat treatment; Structure; Optical; Electrical; ITO FILMS; SUBSTRATE-TEMPERATURE; SOLAR-CELLS; COATINGS; SENSOR; GLASS;
D O I
10.1016/j.surfcoat.2010.10.062
中图分类号
TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
Post-annealed optimized RF-sputtered indium-tin-oxide (ITO) films were further treated at high temperature environments to investigate the effects of multiple heat treatment cycles on their structure, optical and electrical properties. Identification of intrinsic changes to the ITO characteristics is crucial because ITO films are eventually used in further applications that involve more treatment processes, which in turn, could alter the initial optimized properties. After further heating the post-annealed optimized films in atmospheric air, a red-shift occurred in the optical transmittance with a narrowed bandgap energy from 4.00 eV to 3.94 eV due to decrease in the free electron charge density caused by the growth of ITO crystal grains. Additional heating at temperatures more than 300 degrees C was also found to increase the electrical sheet resistance of the ITO rapidly from 13.4 Omega per square at 300 degrees C up to 54.1 Omega per square at 600 degrees C. The results indicate that the ITO electrical conductivity is more greatly influenced by the decrease of the electrically active tin dopant concentration and oxygen vacancies than by improvement of its crystallinity and stoichiometry. This work provides fundamental insights regarding multiple heat treatments of ITO thin films. (C) 2010 Elsevier B.V. All rights reserved.
引用
收藏
页码:2852 / 2856
页数:5
相关论文
共 41 条
[1]   Characterization of rf-sputtered indium tin oxide thin films [J].
Bhatti, MT ;
Rana, AM ;
Khan, AF .
MATERIALS CHEMISTRY AND PHYSICS, 2004, 84 (01) :126-130
[2]   Comparison of spray pyrolyzed FTO, ATO and ITO coatings for flat and bent glass substrates [J].
Bisht, H ;
Eun, HT ;
Mehrtens, A ;
Aegerter, MA .
THIN SOLID FILMS, 1999, 351 (1-2) :109-114
[3]   TRANSPARENT CONDUCTORS - A STATUS REVIEW [J].
CHOPRA, KL ;
MAJOR, S ;
PANDYA, DK .
THIN SOLID FILMS, 1983, 102 (01) :1-46
[4]   The fabrication of dipped CdS and sputtered ITO thin films for photovoltaic solar cells [J].
Cui, HN ;
Xi, SQ .
THIN SOLID FILMS, 1996, 288 (1-2) :325-329
[5]   Effect of substrate temperature on the surface structure, composition and morphology of indium-tin oxide films [J].
de Carvalho, CN ;
do Rego, AMB ;
Amaral, A ;
Brogueira, P ;
Lavareda, G .
SURFACE & COATINGS TECHNOLOGY, 2000, 124 (01) :70-75
[6]   Effect of substrate temperature on electrical, structural, optical and cathodoluminescent properties of In2O3-Sn thin films prepared by spray pyrolysis [J].
El Hichou, A ;
Kachouane, A ;
Bubendorff, JL ;
Addou, M ;
Ebothe, J ;
Troyon, M ;
Bougrine, A .
THIN SOLID FILMS, 2004, 458 (1-2) :263-268
[7]   The effect of sputtering pressure on electrical, optical and structure properties of indium tin oxide on glass [J].
Elhalawaty, S. ;
Siyaramakrishnan, K. ;
Theodore, N. D. ;
Alford, T. L. .
THIN SOLID FILMS, 2010, 518 (12) :3326-3331
[8]   NEUTRAL IMPURITY SCATTERING IN SEMICONDUCTORS [J].
ERGINSOY, C .
PHYSICAL REVIEW, 1950, 79 (06) :1013-1014
[9]   Electrical and optical properties of electron beam evaporated ITO thin films [J].
George, J ;
Menon, CS .
SURFACE & COATINGS TECHNOLOGY, 2000, 132 (01) :45-48
[10]   IONIZED IMPURITY SCATTERING IN SEMICONDUCTORS [J].
GERLACH, E ;
RAUTENBERG, M .
PHYSICA STATUS SOLIDI B-BASIC RESEARCH, 1978, 86 (02) :479-482