Rare-earth-doped GaN switchable color electroluminescent devices

Switchable color (SC) light emission has been obtained from thin-film electroluminescent devices (ELDs) which use green Er- and red Eu-doped GaN phosphors. These two-electrode SCELDs can switch color through variation of applied bias. Different SCELD structures, which share in common a stacked GaN: Er/GaN: Eu phosphor layer, can be implemented for use with DC or AC operation. A single SCELD can emit green (537/558 nm), red (622 nm), yellow, and orange. For the DC-SCELD, an electrically rectifying GaN/p-Si interface allows polarity-dependent current paths, which induce selective luminescence of red or green phosphor layers. For the AC-SCELD, as the bias frequency is increased, bright red emission from GaN: Eu saturates while green emission from GaN: Er increases and becomes dominant. The AC-SCELD exhibits brightness levels >10 cd/m/sup 2/ and can change chromaticity coordinates by as much as /spl Delta/x>0.32 and /spl Delta/y>0.33. Application of these devices to switching between other visible and/or infrared wavelengths is envisioned based on appropriate choice of luminescent dopants in the GaN layers.

[1]  A. Steckl,et al.  Comparison of the optical properties of Er{sup 3+} doped gallium nitride prepared by metalorganic molecular beam epitaxy (MOMBE) and solid source molecular beam epitaxy (SSMBE) , 1999 .

[2]  A. Steckl,et al.  Local structure and bonding of Er in GaN: A contrast with Er in Si , 2000 .

[3]  J. Kalinowski,et al.  Voltage-induced evolution of emission spectra in organic light-emitting diodes , 1998 .

[4]  A. Krasnov.  Selection of dielectrics for alternating-current thin-film electroluminescent device , 1999 .

[5]  G. O. Müller.  Thin film electroluminescence , 1993 .

[6]  A. Steckl,et al.  Alternating current thin-film electroluminescence of GaN:Er , 2000 .

[7]  Andrew J. Steckl,et al.  Red light emission by photoluminescence and electroluminescence from Pr-doped GaN on Si substrates , 1999 .

[8]  J. Sturm,et al.  Integrated three-color organic light-emitting devices , 1996 .

[9]  Stephen R. Forrest,et al.  Transparent stacked organic light emitting devices. II. Device performance and applications to displays , 1999 .

[10]  K. Brennan,et al.  Comparison of electron and hole initiated impact ionization in zincblende and wurtzite phase gallium nitride , 1997 .

[11]  Paul H. Holloway,et al.  The structure, device physics, and material properties of thin film electroluminescent displays , 1998 .

[12]  A. Steckl,et al.  Optoelectronic Properties and Applications of Rare-Earth-Doped GaN , 1999 .

[13]  A. Steckl,et al.  Rare Earth Doped Gallium Nitride — Light Emission from Ultraviolet to Infrared , 2000 .

[14]  Y. Hamakawa.  A technological evolution from bulk crystalline age to multilayered thin film age in optoelectronic devices , 1996 .

[15]  A. Steckl,et al.  Comparison of the Optical Properties of Er3+ Doped Gallium Nitride Prepared by Metalorganic Molecular Beam Epitaxy (Mombe) and Solid Source Molecular Beam Epitaxy (SSMBE) , 2000 .

[16]  Teruyoshi Mizutani,et al.  Preparation and properties of an organic light emitting diode with two emission colors dependent on the voltage polarity , 1996 .

[17]  A. Steckl,et al.  Voltage-controlled yellow or orange emission from GaN codoped with Er and Eu , 2000 .

[18]  Qibing Pei,et al.  Voltage controlled two color light‐emitting electrochemical cells , 1996 .

[19]  K. Yoshino,et al.  Three‐layered multicolor organic electroluminescent device , 1996 .

[20]  Jason Heikenfeld,et al.  Blue emission from Tm-doped GaN electroluminescent devices , 1999 .

[21]  Josef C. Lapp.  Glass substrates for AMLCD applications: properties and implications , 1997, Electronic Imaging.

[22]  C. R. Abernathy,et al.  Luminescence characteristics of Er-doped GaN semiconductor thin films , 2000 .

[23]  Yutaka Ohmori,et al.  Color-Variable Light-Emitting Diode Utilizing Conducting Polymer Containing Fluorescent Dye , 1993 .

[24]  A. Steckl,et al.  Electroluminescent devices using a high-temperature stable GaN-based phosphor and thick-film dielectric layer , 2002 .

[25]  C. Schaus,et al.  Electroluminescent displays , 1991, Summaries of papers presented at the Conference on Lasers and Electro-Optics.

[26]  Yoshimasa A. Ono,et al.  Electroluminescent Displays , 1995 .

[27]  Transparent stacked organic light emitting devices. I. Design principles and transparent compound electrodes , 1999 .

[28]  A. Steckl,et al.  Green electroluminescence from Er-doped GaN Schottky barrier diodes , 1998 .

[29]  Omesh Sahni.  Thin Film Electroluminescent Devices With Memory , 1983, Photonics West - Lasers and Applications in Science and Engineering.

[30]  Ram W Sabnis,et al.  Color filter technology for liquid crystal displays , 1999 .

[31]  Jason Heikenfeld,et al.  Red light emission by photoluminescence and electroluminescence from Eu-doped GaN , 1999 .

[32]  A. Steckl,et al.  Low-voltage GaN:Er green electroluminescent devices , 2000 .