Effects of film morphology on ambipolar transport of top- gate-type polymer light-emitting transistors utilizing ambipolar polymer-blend films

Author

Kajii, Hirotake ; Koiwai, Kyohei ; Tanaka, Hiroya ; Ohmori, Yutaka

Author_Institution

Grad. Sch. of Eng., Osaka Univ., Suita, Japan

fYear

2013

fDate

2-5 July 2013

Firstpage

171

Lastpage

174

Abstract

The effects of film morphology on ambipolar transport of top-gate-type polymer light-emitting transistors utilizing blended fluorene-type polymers of poly(9,9-dioctylfluorene) (F8) and poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT) were investigated. All devices based on ambipolar polymer-blend films with various blend ratios as the active layer exhibited the ambipolar and light-emitting characteristics. The morphology of blended films changed markedly with the blend ratio and annealing temperature. Hole mobilities of the devices with F8:F8BT blended films are independent of film morphology. The difference of behavior of electron mobility in the F8:F8BT devices resulted from the major morphological differences of surface structure that the channel can be considered to be formed. F8BT molecules in F8 act as electron trap sites owing to the wide gap between F8 and F8BT LUMO levels.

Keywords

annealing; bipolar transistors; electron mobility; electron traps; hole mobility; light emitting devices; organic field effect transistors; organic semiconductors; polymer blends; polymer films; surface morphology; thin film transistors; F8:F8BT blended films; LUMO levels; active layer; ambipolar characteristics; ambipolar polymer-blend films; ambipolar transport; annealing temperature; blend ratios; blended fluorene-type polymers; electron mobility; electron trap; film morphology; hole mobilities; light-emitting characteristics; poly(9,9-dioctylfluorene); poly(9,9-dioctylfluorene-co-benzothiadiazole); surface structure; top-gate polymer light-emitting transistors; Annealing; Charge carrier processes; Electrodes; Films; Logic gates; Morphology; Polymers;

fLanguage

English

Publisher

ieee

Conference_Titel

Active-Matrix Flatpanel Displays and Devices (AM-FPD), 2013 Twentieth International Workshop on

Conference_Location

Kyoto

Type

conf

Filename

6617807