Regensburg 2013 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

HL: Fachverband Halbleiterphysik

HL 83: Transport I

HL 83.2: Talk

Thursday, March 14, 2013, 15:15–15:30, H16

Increased Stability of Solution Processed ZnO TFTs by Selectively Bonded Diketones — •Marlis Ortel, Nataliya Kalinovich, Gerd Röschenthaler, and Veit Wagner — Research Center for Functional Materials and Nanomolecular Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany

10nm thick nano-crystalline ZnO layers were deposited by spray pyrolysis in TFT configuration in order to investigate the impact of surface states on the TFT performance. Surface trap states are known to have significant influence on mobility, hysteresis and operational stability of transistors. Diketone molecules were applied to the surface, which are known to bind selectively to zinc ions in order to reduce the trap state density. It was found that the electronic structure of the semiconductor was tuned depending on the functional groups attached to the diketone. Transistors coated with 4,4,4-trifluoro-1-phenylbutane-1,2-dione were found to stabilize the TFT performance even under long term gate bias stress. Furthermore the mobility was significantly increased by 30% to 9cm2V-1s-1 after few seconds of exposure to the chemical compound. Hence diketones are concluded to be suitable materials to minimize trapping process in zinc oxide which leads to strongly improved device characteristics.