An Organic Light‐Emitting Diode with Field‐Effect Electron Transport

In Chapter 3, a novel two-electrode light-emitting device structure is proposed. The device is a hybrid structure between a diode and a field-effect transistor. Compared to conventional OLEDs, the cathode is displaced one to several micrometers from the light-emission zone. As the light emission zone is not covered by metal, the device can be used for top emission or even as waveguide. The micrometer-sized distance between the cathode and the active region can be bridged by electrons with an enhanced field-effect mobility. Owing to this high charge carrier mobility, large current densities are possible. The external quantum efficiency at these high current densities is as high as that of conventional OLEDs using the same materials. In contrast to organic light-emitting field-effect transistors, only two electrodes are used. Moreover, lightemission in the novel device structure always occurs at a fixed position, irrespective of the applied bias, in contrast to LEOFETs where the emission zone can move within the channel by varying the bias conditions. The first section of this chapter describes the technology and the materials used to fabricate the device. Next, the device operation and the device performance are discussed. The electrical characteristics as well as the opto-electronic performance are studied. Suggestions for further improvement of the device performance are given in the last section of this chapter.

[1]  Yoshio Taniguchi,et al.  High mobility n-type thin-film transistors based on N,N′-ditridecyl perylene diimide with thermal treatments , 2006 .

[2]  D. Gundlach,et al.  High mobility n-channel organic thin-film transistors and complementary inverters , 2005 .

[3]  Richard H. Friend,et al.  Spatial control of the recombination zone in an ambipolar light-emitting organic transistor , 2006 .

[4]  R. Zamboni,et al.  Ambipolar organic light-emitting transistors employing heterojunctions of n-type and p-type materials as the active layer , 2006 .

[5]  P. Blom,et al.  Electrical characterization of polymer light-emitting diodes , 1998 .

[6]  Fabio Biscarini,et al.  Spatially correlated charge transport in organic thin film transistors. , 2004, Physical review letters.

[7]  Christof Pflumm,et al.  The influence of annihilation processes on the threshold current density of organic laser diodes , 2007 .

[8]  M. Gerken,et al.  Amplified spontaneous emission in an organic semiconductor multilayer waveguide structure including a highly conductive transparent electrode , 2005 .

[9]  T. Jackson,et al.  Pentacene organic thin-film transistors-molecular ordering and mobility , 1997, IEEE Electron Device Letters.

[10]  Volker Wittwer,et al.  Low-threshold polymeric distributed feedback lasers with metallic contacts , 2004 .

[11]  Heinz von Seggern,et al.  Light-emitting field-effect transistor based on a tetracene thin film. , 2003, Physical review letters.

[12]  Alberto Piqué,et al.  Transparent conducting aluminum-doped zinc oxide thin films for organic light-emitting devices , 2000 .

[13]  R. Friend,et al.  Picosecond time-resolved photoluminescence of PPV derivatives , 1997 .

[14]  Siegfried Karg,et al.  Ambipolar organic field-effect transistor based on an organic heterostructure , 2004 .

[15]  Stephen R. Forrest,et al.  Phosphorescent materials for application to organic light emitting devices , 1999 .

[16]  Yoshiaki Oku,et al.  Lateral organic light-emitting diode with field-effect transistor characteristics , 2005 .

[17]  Daniel Moses,et al.  Light emission in the channel region of a polymer thin-film transistor fabricated with gold and aluminum for the source and drain electrodes , 2005 .

[18]  P. Heremans,et al.  Organic Light‐Emitting Diodes with Field‐Effect‐Assisted Electron Transport Based on α‐bi;,ω‐bi;‐Diperfluorohexyl‐quaterthiophene , 2008 .

[19]  R. Capelli,et al.  High‐Mobility Ambipolar Transport in Organic Light‐Emitting Transistors , 2006 .

[20]  Nir Tessler,et al.  Lasers Based on Semiconducting Organic Materials , 1999 .

[21]  E. W. Meijer,et al.  Two-dimensional charge transport in self-organized, high-mobility conjugated polymers , 1999, Nature.

[22]  D. Moses,et al.  High performance light emitting transistors , 2008 .

[23]  Stephen R. Forrest,et al.  A metal-free cathode for organic semiconductor devices , 1998 .

[24]  C. Tang,et al.  Organic Electroluminescent Diodes , 1987 .

[25]  Jan Genoe,et al.  Ambipolar injection in a submicron-channel light-emitting tetracene transistor with distinct source and drain contacts , 2005 .

[26]  Kris Myny,et al.  Integrated shadow mask method for patterning small molecule organic semiconductors , 2006 .

[27]  Y. Hamada,et al.  Red organic light-emitting diodes using an emitting assist dopant , 1999 .

[28]  P. Blom,et al.  Unification of the hole transport in polymeric field-effect transistors and light-emitting diodes. , 2003, Physical review letters.

[29]  T. Riedl,et al.  Loss reduction in fully contacted organic laser waveguides using TE2 modes , 2007 .

[30]  H. Tada,et al.  Field-effect transistors based on poly(p-phenylenevinylene) derivatives , 2004 .

[31]  P. Heremans,et al.  Light-emitting organic field-effect transistor using an organic heterostructure within the transistor channel , 2006 .

[32]  S. Forrest,et al.  Structures for organic diode lasers and optical properties of organic semiconductors under intense optical and electrical excitations , 2000, IEEE Journal of Quantum Electronics.

[33]  H. Sirringhaus,et al.  Efficient Top‐Gate, Ambipolar, Light‐Emitting Field‐Effect Transistors Based on a Green‐Light‐Emitting Polyfluorene , 2006 .

[34]  Heinz von Seggern,et al.  Light emission from a polymer transistor , 2004 .

[35]  P. Blom,et al.  Electro-optical properties of a polymer light-emitting diode with an injection-limited hole contact , 2003 .

[36]  Michele Muccini,et al.  Tetracene-based organic light-emitting transistors: optoelectronic properties and electron injection mechanism , 2004 .

[37]  C.-H. Chen,et al.  Recent progress of molecular organic electroluminescent materials and devices , 2002 .

[38]  D Murphy,et al.  Highly phosphorescent bis-cyclometalated iridium complexes: synthesis, photophysical characterization, and use in organic light emitting diodes. , 2001, Journal of the American Chemical Society.

[39]  M. Muccini.  A bright future for organic field-effect transistors , 2006, Nature materials.

[40]  H. Sirringhaus,et al.  A gate dielectric that enables high ambipolar mobilities in polymer light-emitting field-effect transistors , 2008 .

[41]  Michele Muccini,et al.  Ambipolar light-emitting organic field-effect transistor , 2004 .

[42]  C. H. Chen,et al.  Electroluminescence of doped organic thin films , 1989 .

[43]  Ian D. Parker,et al.  Carrier tunneling and device characteristics in polymer light‐emitting diodes , 1994 .

[44]  S. Forrest,et al.  Nearly 100% internal phosphorescence efficiency in an organic light emitting device , 2001 .

[45]  Piers Andrew,et al.  Photonic band structure and emission characteristics of a metal-backed polymeric distributed feedback laser , 2002 .

[46]  Chihaya Adachi,et al.  High current density in light-emitting transistors of organic single crystals. , 2008, Physical review letters.

[47]  Michele Muccini,et al.  Light-emitting ambipolar organic heterostructure field-effect transistor , 2004 .

[48]  Stephen R. Forrest,et al.  Bright, saturated, red-to-yellow organic light-emitting devices based on polarization-induced spectral shifts , 1998 .

[49]  Junji Kido,et al.  Fabrication of highly efficient organic electroluminescent devices , 1998 .

[50]  T. Jackson,et al.  Stacked pentacene layer organic thin-film transistors with improved characteristics , 1997, IEEE Electron Device Letters.

[51]  Alan J. Heeger,et al.  Light emission from an ambipolar semiconducting polymer field-effect transistor , 2005 .

[52]  Tetsuo Tsutsui,et al.  Electroluminescence in Organic Films with Three-Layer Structure , 1988 .

[53]  Janos Veres,et al.  Air Stable, Amorphous Organic Films and their Applications to Solution Processable Flexible Electronics , 2001 .

[54]  Stephen R. Forrest,et al.  Study of lasing action based on Förster energy transfer in optically pumped organic semiconductor thin films , 1998 .

[55]  Hiroshi Tokailin,et al.  Transient behavior of organic thin film electroluminescence , 1992 .

[56]  Paul F. Baude,et al.  High Performance Organic Thin Film Transistors , 2003 .

[57]  Hidetoshi Yamamoto,et al.  Amplified spontaneous emission under optical pumping from an organic semiconductor laser structure equipped with transparent carrier injection electrodes , 2004 .

[58]  W. Riess,et al.  Tuning Optoelectronic Properties of Ambipolar Organic Light‐ Emitting Transistors Using a Bulk‐Heterojunction Approach , 2006 .

[59]  L. Torsi,et al.  Molecular orbital energy level engineering in organic transistors , 1996 .

[60]  Ardie D. Walser,et al.  Bimolecular reactions of singlet excitons in tris(8-hydroxyquinoline) aluminum , 1996 .

[61]  Richard H. Friend,et al.  General observation of n-type field-effect behaviour in organic semiconductors , 2005, Nature.

[62]  T. Riedl,et al.  Low loss contacts for organic semiconductor lasers , 2006 .