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New concepts for light emitting transistors

Hepp, Aline ; Ahles, Marcus ; Heil, Holger ; Schmechel, Roland ; Weiler, Ulrich ; Mayer, Thomas ; Jaegermann, Wolfram
Dodabalapur, Ananth (ed.) :

New concepts for light emitting transistors.
[Online-Edition: http://proceedings.spiedigitallibrary.org/proceeding.aspx?ar...]
In: Organic field-effect transistors III , 5522 . SPIE , Bellingham, Wash.
[Konferenz- oder Workshop-Beitrag], (2004)

Offizielle URL: http://proceedings.spiedigitallibrary.org/proceeding.aspx?ar...

Kurzbeschreibung (Abstract)

In this study we report on new concepts to generate light emission in organic thin film transistors. The initial physical understanding of light emission from tetracene based field-effect transistors was proposed to be originated from a strong underetching of the drain and source electrodes. This underetched electrodes in combination with the evaporated tetracene is thereby believed to generate a virtual OLED at the drain electrode. Accumulated holes have to leave the gate oxide interface to reach the drain electrode by crossing the bulk of the organic semiconductor. Light then occurs by injection of electrons in a large electric field in the bulk. Today's transistors do not show the underetching anymore but are still emitting light only at the drain electrode, again supporting the initial interpretation of a defect state at the edge of the drain electrode. In this context the question how electrons can overcome a potential barrier of 2.7 eV is still open. Therefore an investigation of the gold tetracene interface by UPS and XPS techniques has been started and preliminary data indicate the unexpected result that the barrier for electrons is comparable to that for holes. In a further step the generation of an ambipolar transistor by interface doping with calcium was tried and an n-type pentacene transistor could be fabricated but the strategy failed for tetracene. Finally an electrochemical interface doping was performed by the application of Lithium triflate in PEO to a thin interface layer between gate oxide and tetracene. This leads to light emission but unfortunately also to the loss of the gate voltage influence. Based on these results a possible strategy will be presented.

Typ des Eintrags: Konferenz- oder Workshop-Beitrag (Keine Angabe)
Erschienen: 2004
Herausgeber: Dodabalapur, Ananth
Autor(en): Hepp, Aline ; Ahles, Marcus ; Heil, Holger ; Schmechel, Roland ; Weiler, Ulrich ; Mayer, Thomas ; Jaegermann, Wolfram
Titel: New concepts for light emitting transistors
Sprache: Englisch
Kurzbeschreibung (Abstract):

In this study we report on new concepts to generate light emission in organic thin film transistors. The initial physical understanding of light emission from tetracene based field-effect transistors was proposed to be originated from a strong underetching of the drain and source electrodes. This underetched electrodes in combination with the evaporated tetracene is thereby believed to generate a virtual OLED at the drain electrode. Accumulated holes have to leave the gate oxide interface to reach the drain electrode by crossing the bulk of the organic semiconductor. Light then occurs by injection of electrons in a large electric field in the bulk. Today's transistors do not show the underetching anymore but are still emitting light only at the drain electrode, again supporting the initial interpretation of a defect state at the edge of the drain electrode. In this context the question how electrons can overcome a potential barrier of 2.7 eV is still open. Therefore an investigation of the gold tetracene interface by UPS and XPS techniques has been started and preliminary data indicate the unexpected result that the barrier for electrons is comparable to that for holes. In a further step the generation of an ambipolar transistor by interface doping with calcium was tried and an n-type pentacene transistor could be fabricated but the strategy failed for tetracene. Finally an electrochemical interface doping was performed by the application of Lithium triflate in PEO to a thin interface layer between gate oxide and tetracene. This leads to light emission but unfortunately also to the loss of the gate voltage influence. Based on these results a possible strategy will be presented.

Buchtitel: SPIE Proceedings
Reihe: Organic field-effect transistors III
Band: 5522
Ort: Bellingham, Wash.
Verlag: SPIE
Freie Schlagworte: Calcium, Doping, Electrodes, Electrons, Gold, Interfaces, Lithium, Organic light emitting diodes, Organic semiconductors, Oxides.
Fachbereich(e)/-gebiet(e): Fachbereich Material- und Geowissenschaften > Materialwissenschaften > Elektronische Materialeigenschaften
Fachbereich Material- und Geowissenschaften > Materialwissenschaften > Oberflächenforschung / Surface Science
Fachbereich Material- und Geowissenschaften > Materialwissenschaften
Fachbereich Material- und Geowissenschaften
Veranstaltungsort: Denver, Colorado, USA
Veranstaltungsdatum: August 02, 2004
Hinterlegungsdatum: 20 Nov 2008 08:19
Offizielle URL: http://proceedings.spiedigitallibrary.org/proceeding.aspx?ar...
ID-Nummer: 10.1117/12.566541
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