Improvement in Output Power of 280-nm Deep Ultraviolet Light-Emitting Diode by Using AlGaN Multi Quantum Wells

We fabricated high-output-power 280-nm light-emitting diodes (LEDs) by employing high-crystal-quality AlN templates and optimized epitaxial structures. The emission wavelength, output power, forward voltage, spectral linewidth, and external quantum efficiency of the fabricated device measured at 20 mA were 281.0 nm, 2.45 mW, 7.53 V, 10.6 nm, and 2.78%, respectively. In the case of DC operation, the output power increased with time probably resulting from enhanced p-type activation by junction heating. We also fabricated a multi-chip device which consisted of 26 small-chip LEDs. It produced 223 mW at a pulse injection current of 1850 mA.

[1]  Tomoaki Ohashi,et al.  231–261nm AlGaN deep-ultraviolet light-emitting diodes fabricated on AlN multilayer buffers grown by ammonia pulse-flow method on sapphire , 2007 .

[2]  H. Hirayama,et al.  227 nm AlGaN Light-Emitting Diode with 0.15 mW Output Power Realized using a Thin Quantum Well and AlN Buffer with Reduced Threading Dislocation Density , 2008 .

[3]  Y. Aoyagi,et al.  AlN/AlGaN short-period superlattice sacrificial layers in laser lift-off for vertical-type AlGaN-based deep ultraviolet light emitting diodes , 2009 .

[4]  M. Shur,et al.  247 nm Ultra-Violet Light Emitting Diodes , 2007 .

[5]  V. Adivarahan,et al.  Vertical Injection Thin Film Deep Ultraviolet Light Emitting Diodes with AlGaN Multiple-Quantum Wells Active Region , 2009 .

[6]  Y. Taniyasu,et al.  An aluminium nitride light-emitting diode with a wavelength of 210 nanometres , 2006, Nature.

[7]  Takashi Mukai,et al.  Improvement of Luminous Efficiency in White Light Emitting Diodes by Reducing a Forward-bias Voltage , 2007 .

[8]  Hong Wang,et al.  Pulsed atomic-layer epitaxy of ultrahigh-quality AlxGa1−xN structures for deep ultraviolet emissions below 230 nm , 2002 .

[9]  Manijeh Razeghi,et al.  High-power 280 nm AlGaN light-emitting diodes based on an asymmetric single-quantum well , 2004 .

[10]  Hideki Hirayama,et al.  Quaternary InAlGaN-based high-efficiency ultraviolet light-emitting diodes , 2005 .

[11]  Monirul Islam,et al.  280 nm Deep Ultraviolet Light Emitting Diode Lamp with an AlGaN Multiple Quantum Well Active Region , 2009 .

[12]  Xiaobo Sharon Hu,et al.  Deep ultraviolet light‐emitting diodes , 2006 .

[13]  Motoaki Iwaya,et al.  Influence of High Temperature in the Growth of Low Dislocation Content AlN Bridge Layers on Patterned 6H-SiC Substrates by Metalorganic Vapor Phase Epitaxy , 2007 .

[14]  Robert Kaplar,et al.  Room-temperature direct current operation of 290 nm light-emitting diodes with milliwatt power levels , 2004 .

[15]  David W. Weyburne,et al.  Correlation between optoelectronic and structural properties and epilayer thickness of AlN , 2007 .

[16]  Makoto Miyoshi,et al.  Suppression of the subband parasitic peak by 1nm i-AlN interlayer in AlGaN deep ultraviolet light-emitting diodes , 2008 .

[17]  Makoto Miyoshi,et al.  AlGaN-Based Deep Ultraviolet Light-Emitting Diodes Grown on Epitaxial AlN/Sapphire Templates , 2008 .

[18]  M. Asif Khan,et al.  III–Nitride UV Devices , 2005 .

[19]  M. Shur,et al.  Near-band-edge photoluminescence of wurtzite-type AlN , 2002 .