Study of trap states in zinc oxide (ZnO) thin films for electronic applications

• Author(s): Casteleiro, C. ; Gomes, Henrique L. ; Stallinga, Peter ; Bentes, L. ; Ayouchi, R. ; Schwarz, R.
• Date: 2008
• Persistent ID: http://hdl.handle.net/10400.1/3298
• Origin: Sapientia - Universidade do Algarve
• Subject(s): Thin film transistors; Thermally stimulated and depolarization current; Laser deposition; Defects
• Document Type: Article
• Language: English

Description

The electrical properties of ZnO thin films grown by pulsed laser deposition were studied. Field-effect devices with a mobility reaching 1 cm2/V s show non-linearities both in the current–voltage and in the transfer characteristics which are explained as due to the presence of trap states. These traps cause a reversible threshold voltage shift as revealed by low-frequency capacitance–voltage measurements in metal insulator semiconductor (MIS) capacitors. Thermal detrapping experiments in heterojunctions confirm the presence of a trap state located at 0.32 eV.