AVS 47th International Symposium
    Thin Films Thursday Sessions
       Session TF-ThA

Paper TF-ThA4
Properties of Transparent conducting CdO-In@sub 2@O@sub 3@-SnO@sub 2@ Thin Films Prepared by Pulse Laser Deposition (PLD)

Thursday, October 5, 2000, 3:00 pm, Room 203

Session: Transparent Optical Coatings
Presenter: M. Yan, Northwestern University
Authors: M. Yan, Northwestern University
R.P.H. Chang, Northwestern University
T.O. Mason, Northwestern University
T.J. Marks, Northwestern University
K.R. Poeppelmeier, Northwestern University
Correspondent: Click to Email
Transparent conducting oxides (TCO) have extensive application in display devices, solar cells and sensing elements Various techniques have been applied to deposit TCO films including: thermal evaporation, sputtering, reactive ion plating, chemical vapor deposition (CVD), pulse laser deposition (PLD), atomic layer epitaxy (ALE), etc. The ternary alloy system of CdO-In@sub 2@O@sub 3@-SnO@sub 2@ has received much attention recently. Several compounds in this ternary systems, Cd@sub 2@SnO@sub 4@, CdIn@sub 2@O@sub 4@ and In@sub 4@Sn@sub 3@O@sub 12@, exhibit encouraging electrical and optical properties, while most of the ternary phase diagram (CdO, In@sub 2@O@sub 3@, SnO@sub 2@) remains unexplored. Furthermore, it is believed that there are some metastable phases and solution ranges not available in the bulk form but can be obtained as thin films. In our research, we synthesized and examined the electrical, optical and structural properties of thin films on Si and Corning 1737 substrates with different compositions deposited in a multi-target PLD system. Films were formed by first creating multi-layers of elemental oxides of CdO, In@sub 2@O@sub 3@ and SnO@sub 2@. The stoichiometry of the complex oxide was adjusted during this process. The multi-layered films were then annealed in certain gas environment for a range of time and temperature to form polycrystalline ternary oxides. Preliminary results show that 5% In@sub 2@O@sub 3@ doped CdO has conductivity of 20,000S and bandgap of 2.75eV. Stoichiometric Cd@sub 2@SnO@sub 4@ has conductivity of 1600S and bandgap of 3.02eV. Stoichiometric CdIn@sub 2@O@sub 4@ has conductivity of 600S and bandgap of 3.05eV. When CdIn@sub 2@O@sub 4@ is doped with 5% SnO@sub 2@, its conductivity raised to 3,300S and its bandgap remains unchanged. It is believed that further improvements can be achieved through proper doping and annealing strategies.