Thermopower measurements in the range of 300-650 K along with room temperature optical absorption and electrical resistivity studies have been performed on indium tin oxide (ITO) and manganese doped indium tin oxide (Mn:ITO) thin films grown by reactive DC sputtering. The thermopower of the films measured in Ar ambient displayed irreversible changes attributable to oxygen loss. Thermopower, carrier concentration and resistivity of the films have been found to depend on oxygen vacancies and Mn concentration. The observations have been substantiated with optical absorption and room temperature electrical resistivity results. It has also been observed that band gap tuning in these films is possible by the introduction of Mn as well as oxygen vacancies. © 2009 Elsevier B.V. All rights reserved.

S. Kasi Viswanathan

Department Of Physics

V. Damodara Das

BAND-GAP TUNING

DC SPUTTERING

Diluted magnetic semiconductors

Electrical resistivity

Indium tin oxide

INDIUM TIN OXIDE FILMS

MN CONCENTRATIONS

optical absorption

OPTICAL STUDY

OXYGEN LOSS

Room temperature

Thermopower

THERMOPOWER MEASUREMENTS

THERMOPOWERS

Transparent conducting oxides

Absorption

Carrier concentration

electric conductivity

indium

Light absorption

Magnetic semiconductors

Manganese

Manganese compounds

Oxygen

Oxygen vacancies

Photolithography

Thermoelectric power

Oxide films

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Thin Solid Films

Indium based transparent conducting oxides doped with magnetic elements have been studied intensively in recent years with a view to develop novel ferromagnetic semiconductors for spin-based electronics. In the present work, we have grown manganese doped indium tin oxide (Mn:ITO) thin films, onto Si and Si/SiO2 substrates by DC reactive sputtering of a composite target containing indium-tin alloy and manganese, in a gas mixture of oxygen and argon. Glancing angle X-ray diffraction (GXRD) studies reveal the polycrystalline nature of the films. Magnetic measurements carried out using vibrating sample magnetometer (VSM) suggest that the films are ferromagnetic at room temperature, with a saturation magnetization of ∼22.8 emu/cm3. The atomic percentages of In, Sn, Mn and O, as estimated using Rutherford backscattering spectrometry (RBS) are 37.0, 4.0, 1.6 and 57.4, respectively. RBS measurements reveal that the interface of the films with Si substrate has a ∼30 nm thick intermediate layer. This layer consists of oxygen, silicon, indium, tin and manganese, in the ratio 1:0.56:0.21:0.07:0.03, indicative of diffusion of elements across the interface. The films on Si/SiO2, on the other hand, have a sharp interface. © 2007 Elsevier B.V. All rights reserved.

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms

Ion beam studies on reactive DC sputtered manganese doped indium tin oxide thin films

Present status of transparent conducting oxide thin-film development for Indium-Tin-Oxide (ITO) substitutes

Renewable Energy

Development of thermoelectric oxides for renewable energy conversion technologies

Physica B: Condensed Matter

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Journal of Physics: Condensed Matter

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Thermopower and optical studies on undoped and manganese doped indium tin oxide films

Journal	Thin Solid Films
ISSN	00406090
Open Access	No