Daisuke Iida

April 2024

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  Paper accepted in Phys. Status Solidi A!

  1 min read · Fri, Apr 5 2024

  News

  We report a selective passivation of p-GaN via hydrogen plasma treatment for InGaN single-quantum-well red light-emitting diodes.

December 2023

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  Prestigious international awards for KAUST ECE students

  5 min read · Tue, Dec 12 2023

  Awards News

  KAUST ECE students shine bright, winning prestigious international awards.

November 2023

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  Congratulations! Pavel's paper has been selected for the JSAP Young Scientist Award!

  1 min read · Fri, Nov 17 2023

  News

  His first authored paper "InGaN-based green micro-LED efficiency enhancement by hydrogen passivation of the p-GaN sidewall, Appl. Phys. Expres 15 (2022) 084003" has been selected for the JSAP Young Scientist Award! The JSAP Young Scientist Award is presented to young researchers who have mainly authored excellent papers that are expected to contribute to the progress of applied physics.
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  Congratulations! Cesur received the Best Student Award at ICNS-14 in Japan.

  1 min read · Fri, Nov 17 2023

  News

  Cesur received the Best Student Award at ICNS-14 in Japan. He has a great opportunity to showcase his research on "InGaN Red LEDs Fabricated by Hydrogen Plasma Passivation ". The 14th International Conference on Nitride Semiconductors (ICNS-14) is the biggest conference that presents high-impact scientific and technological advances in materials and devices in group-III nitride semiconductors.
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  Investigation of N-polar InGaN growth on misoriented ScAlMgO4 substrates

  1 min read · Thu, Nov 2 2023

  News

  We report the growth of N-polar InGaN layers on misoriented ScAlMgO4 (SAM) substrates with offset of 0.3 to 5.8o toward the m-plane. We obtained an unprecedented crystalline quality of N-polar InGaN using SAM substrates with a 0.5o offset, which exhibited a 000-2 X-ray rocking curve full width at half maximum value of 223 arcsec.

September 2023

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  Paper accepted in Journal of Physics: Photonics!

  1 min read · Wed, Sep 13 2023

  News

  The report shows the micro-LED roadmap for the next generation of smart displays. The innovation in epitaxial growth technology can provide critical solutions for the micro LED performance in various aspects.

August 2023

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  RGB monolithic GaInN-based μLED arrays connected via tunnel junctions

  1 min read · Fri, Aug 4 2023

  News

  We demonstrated a 330 ppi monolithic RGB micro light-emitting diodes (μLED) array of blue, green, and red GaInN-based LEDs stacked on the same wafer using tunnel junction.
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  Paper accepted in ChemComm!

  1 min read · Tue, Aug 1 2023

  News

  We present results from a study addressing the unbiased water-splitting process and its side reactions on n-GaN-based photoelectrodes decorated with NiOx, FeOx, and CoOx nanoparticles. A water-splitting process with n-GaN-based photoelectrodes results in the generation of hydrogen gas and hydrogen peroxide. Quantification of the water-splitting chemical mechanism gave numerical values indicating an increase in the device performance and restriction of the n-GaN electrocorrosion with surface modifications of n-GaN structures.

July 2023

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  Investigations on the high performance of InGaN red micro-LEDs with single quantum well for visible light communication applications

  1 min read · Fri, Jul 7 2023

  News

  we have demonstrated the potential of InGaN-based red micro-LEDs with single quantum well (SQW) structure for visible light communication applications. The LED device has a superior modulation bandwidth of 424 MHz with a data transmission rate of 800 Mbit/s at an injection current density of 2000 A/cm2. These results demonstrate that InGaN-based SQW red micro-LEDs hold great promise for realizing full-color micro-display and visible light communication applications.

May 2023

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  Structural and optical analyses for InGaN-based red micro-LED

  1 min read · Sat, May 27 2023

  News

  National Yang Ming Chiao Tung University and KAUST Team reported the structural and optical characteristics of a red micro-LED.
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  Improvement of optical properties of InGaN-based red multiple quantum wells

  1 min read · Wed, May 17 2023

  News

  Xiamen University and KAUST Team have optical characterized the high-quality InGaN-based red LED structures by photoluminescence.
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  Our review paper is ranked in the most read!

  1 min read · Wed, May 17 2023

  News

  This review paper in 2022 is still ranked in the Most Read of Semiconductor Science and Technology (IOP Publishing). The paper reviews nitride-based red LEDs and micro-LEDs. The field is growing and getting popular.

April 2023

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  Dr. Daisuke Iida has been appointed as Invited Faculty!

  1 min read · Wed, Apr 12 2023

  News

  Dr. Daisuke Iida has been appointed as Invited Faculty at Center for Integrated Research of Future Electronics (Director: Prof. Hiroshi Amano (Nobel laureate)), Institute of Materials and Systems for Sustainability, Nagoya University

March 2023

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  Received the Japan Society of Applied Physics (JSAP) Outstanding Paper Award 2022!

  1 min read · Thu, Mar 16 2023

  News

  Professor Kazuhiro Group recently received the Japan Society of Applied Physics (JSAP) Outstanding Paper Award 2022. According to the JSAP, the award is presented to “the authors of outstanding papers published in the membership journal, Oyo Buturi, Japanese Journal of Applied Physics, and Applied Physics Express. These awards honor the authors of papers that are regarded as exceptional achievements in applied physics.”
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  Paper accepted in AIP Advances!

  1 min read · Fri, Mar 10 2023

  News

  We have grown high-crystallinity InGaN layers on ScAlMgO4 (SAM) substrates using metalorganic vapor-phase epitaxy. We have prepared atomically flat SAM substrates by cleaving them along the c-plane and have utilized direct InGaN growth without any low-temperature buffer layer. The resulting InGaN layer has a distinct hexagonal hillock morphology and remarkable crystalline quality.

December 2022

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  Congratulations! New Journal of Chemistry adopts Artem’s work as the cover page.

  1 min read · Tue, Dec 13 2022

  News

  The New Journal of Chemistry is for new directions in chemistry. The latest issue (volume 46, Nover 48) has adopted scientific art made by Artem Shushanian (a PhD candidate).
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  Paper accepted in Crystals (special issue of the 30th anniversary of Shuji Nakamura’s Contribution to Blue LEDs )

  1 min read · Wed, Dec 7 2022

  News

  We have developed a new LED structure by using hydrogen passivation. The result is accepted in Crystals to the Special Issue "In Celebration of the 30th Anniversary of Shuji Nakamura’s Contribution to Blue Light-emitting Diodes”. The new device showed higher EQE and WPE compared to the conventional LED structures.

November 2022

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  Paper accepted in New Journal of Chemistry!

  1 min read · Mon, Nov 7 2022

  News

  We studied the electrochemical property of nitride semiconductors. It was expected to be the three-electron nature so far. However, we have found out that it is the six-electron nature. The six-electron nature was observed in different solutions and pH levels, resulting in a universal phenomenon for nitride semiconductors. The result will be useful to control electrochemical etching and other treatments to achieve their precise control.

October 2022

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  Dr. Iida, the appointment to the Scientific Reports Editorial Board

  1 min read · Tue, Oct 4 2022

  News

  Dr. Iida has accepted the nomination of the Editorial Board Member of the Scientific Reports, Nature Publishing Group. Scientific Reports is an open-access journal publishing rigorously peer-reviewed research from across the natural sciences, psychology, medicine, and engineering. This journal is one of the highly ranked ones, has a 2-year impact factor: 4.996 (2021), and is the 5th most-cited journal in the world.

September 2022

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  Selected as Invited talk at IWN2022 (Berlin, Germany)

  1 min read · Tue, Sep 13 2022

  News

  Prof. Kazuhiro Ohkawa deliver an invited talk at International Workshop on Nitride Semiconductors (IWN). The IWN is a major conference in the fields of LEDs and Lasers. He is the only invited speaker from Saudi Arabia. Mohammed, Artem, and Daisuke give three oral talks and one poster.
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  Selected as “Highlighted talk” at the Autumn meeting of Japanese Society of Applied Physics.

  1 min read · Tue, Sep 13 2022

  News

  Our Scheduled presentation is selected as “Highlighted talk” at the Autumn meeting of the Japanese Society of Applied Physics. Mohammed Najmi et al., “Structural analysis of N-polar InGaN layer grown on ScAlMgO4 substrate without buffer layer” 23a-E202-10 from 11:45 am March 23 (JPN time) The ratio of the highlighted talks in this conference is usually less than 1%.

June 2022

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  High-efficiency InGaN red micro-LEDs for visible light communication

  1 min read · Mon, Jun 27 2022

  News

  In this study, we present a high-efficiency InGaN red micro-LED fabricated by the incorporation of superlattice structure, atomic layer deposition passivation, and a distributed Bragg reflector, exhibiting maximum external quantum efficiency of 5.02% with a low efficiency droop corresponding to an injection current density of 112 A∕cm2. The fast carrier dynamics in the InGaN is characterized by using time-resolved photoluminescence, which is correlated to a high modulation bandwidth of 271 MHz achieved by a 6× 25-μm-sized micro-LED array with a data transmission rate of 350 Mbit/s at a high injection current density of 2000 A∕cm2. It holds great promise for full-color micro-displays as well as high-speed visible light communication applications based on monolithic InGaN micro-LED technologies.
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  Paper accepted in Applied Physics Letters!

  1 min read · Sat, Jun 18 2022

  News

  In this work, we present the characterization of red InGaN/GaN multiple-quantum-well (MQW) light-emitting diode (LED) structures. The results of photoluminescence (PL) studies show that a thicker n-GaN layer is beneficial for obtaining higher In-content for red MQWs. Our findings imply that in order to achieve high-efficiency InGaN MQWs for red emission, enhancing the uniformity of In-content distribution in the active region and decreasing non-radiative recombination centers are critical challenges.
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  Paper accepted in Materials Science in Semiconductor Processing!

  1 min read · Thu, Jun 16 2022

  News

  The pump and probe technique in Raman spectroscopy is used to demonstrate the phonon transport properties of an In0.05Ga0.95N/GaN heterostructure. This method has the advantage of enabling the study of phonon transport processes inside and at interfaces of films with crystal defects by visualizing the shift of phonon-mode energies due to local heating.
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  Paper accepted in AIP Advances! This paper has been chosen as an Editor's Pick. Congratulations!

  1 min read · Wed, Jun 8 2022

  News

  We report highly efficient InGaN-based red light-emitting diodes (LEDs) grown on conventional c-plane-patterned sapphire substrates. The packaged LED's external quantum efficiency, light-output power, and forward voltage with a 621 nm peak emission wavelength at 20 mA (10.1 A/cm2) injection current were 4.3%, 1.7 mW, and 2.96 V, respectively. This design development represents a valuable contribution to the next generation of micro-LED displays. This paper has been chosen as an Editor's Pick.

May 2022

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  Microstructural analysis of N-polar InGaN directly grown on a ScAlMgO4(0001) substrate

  1 min read · Mon, May 2 2022

  News

  We demonstrated a high crystalline quality of N-polar InGaN layer grown on ScAlMgO4 substrates by metalorganic vapor-phase epitaxy. The results show that the interface between N-polar InGaN and SAM occurs between the O atoms of the O–Sc SAM surface and the (Ga,In) atoms of InGaN.

March 2022

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  Paper accepted in IEEE Journal of Lightwave Technology!

  1 min read · Fri, Mar 18 2022

  News

  We demonstrated that the InGaN-based red resonant cavity LEDs exhibited optical resonant effect, a high Q factor (~3010), and a narrow emission linewidth (FMHW ~0.2 nm), indicating low optical loss in the resonant cavity.
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  Congratulations! Selected as “Highlighted talk” at the Spring meeting of Japanese Society of Applied Physics in Spring 2022.

  1 min read · Wed, Mar 9 2022

  News

  Our Scheduled presentation is selected as “Highlighted talk” at the Spring meeting of the Japanese Society of Applied Physics in Spring 2022. Daisuke Iida et al., “” 23a-E202-10 from 11:45 am March 23 (JPN time) The ratio of the highlighted talks in this conference is usually less than 1%.

January 2022

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  Passivation of Surface States in GaN by NiO Particles

  1 min read · Thu, Jan 27 2022

  News

  we characterized the surface states in GaN by EIS analyses and demonstrated that NiO particles deposited directly on GaN passivate them. These surface states are generated by the electronic bindings of superficial Ga atoms, and the interaction of those atoms with NiO modifies its chemical structure, as demonstrated by XPS measurements.
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  Paper accepted in RSC Advances!

  1 min read · Tue, Jan 25 2022

  News

  The paper reports the investigation of the wet electrochemical etching of n-GaN films in oxalic acid. The results of a number of quantitative physicochemical analysis methods of the products indicated a 6-electron nature of the etching reaction and fully revealed the mechanism of EC oxidation of n-GaN, which includes the formation of intermediates formed by adsorption of the solvent on GaN surface. Clear understanding of this reaction creates a solid foundation for the investigation of transformations of more complicated III-nitride systems for low-damage and high-precision processing of nitride-based devices.
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  Study on the effect of size on InGaN red micro-LEDs

  1 min read · Mon, Jan 3 2022

  News

  In this research, five sizes (100 × 100, 75 × 75, 50 × 50, 25 × 25, 10 × 10 μm2) of InGaN red micro-light emitting diode (LED) dies are produced using laser-based direct writing and maskless technology. It is observed that with increasing injection current, the smaller the size of the micro-LED, the more obvious the blue shift of the emission wavelength. When the injection current is increased from 0.1 to 1 mA, the emission wavelength of the 10 × 10 μm2 micro-LED is shifted from 617.15 to 576.87 nm. The obvious blue shift is attributed to the stress release and high current density injection.

September 2021

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  Investigation of a Separated Short-Wavelength Peak in InGaN Red Light-Emitting Diodes

  1 min read · Thu, Sep 9 2021

  News

  The paper reports the investigation of the electroluminescence properties of the additional peak in the EL spectrum of InGaN-based red LED structure. These results were helpful for understanding the EL performance of the red InGaN QWs and may be useful as guidelines to improve the quality of high-In-content QWs in the future.

August 2021

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  Photoluminescence of InGaN-based red multiple quantum wells

  1 min read · Wed, Aug 25 2021

  News

  The paper reports the investigation of the optical properties of InGaN-based red LED structure with a blue pre-well by measuring the excitation energy and temperature dependent photoluminescence (PL) spectra. The deep localization of quasi-QD structures suppresses efficiently the escape of carriers and then enhances the emission in the red, which is the reason for strong emission intensity. The variation of internal quantum efficiency with excitation intensities indicates the better crystal quality of blue pre-well and the occurrence of defects in the red-emitting structures. The experimental results will provide a useful guidance to fabricate a longer wavelength InGaN-based optoelectronic devices with high-quantum efficiency.
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  Improved performance of InGaN-based red light-emitting diodes by micro-hole arrays

  1 min read · Mon, Aug 23 2021

  News

  The paper reports the luminescence improvement of InGaN-based red LEDs by introducing a micro-hole array. This technique provides the improvement of the internal quantum efficiency and light extraction efficiency. The InGaN-based red LEDs are very attractive for next-generation micro-LED display, because the material is a family of blue and green LEDs.
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  Paper accepted in Optics Letters!

  1 min read · Thu, Aug 19 2021

  News

  The paper reports the new device fabrication for the green micro-LEDs. The micro-LEDs have recently gathered considerable interest for next-generation display applications, such as smartphones and watches, augmented reality (AR), and virtual reality (VR) devices. ​
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  Top Cited Paper Award (Saudi Arabia) from IOP Publishing

  1 min read · Fri, Aug 13 2021

  News

  As one of the most cited articles from Saudi Arabia published across the entire IOP Publishing journal portfolio in 2020, using citations recorded in Web of Science “Demonstration of low forward voltage InGaN-based red LEDs” D. Iida, Z. Zhuang, P. Kirilenko, M. Velazquez-Rizo, and K. Ohkawa, Applied Physics Express 13, 031001 (2020).
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  Paper accepted in Japanese Journal of Applied Physics (Invited review)!

  1 min read · Mon, Aug 2 2021

  News

  In this paper, we review our recent progress on InGaN-based red LEDs, including the epitaxial structures and device fabrication. We also present the optical performance of InGaN red LEDs with different chip sizes from hundreds to tens of micrometers.

July 2021

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  630-nm red InGaN micro-light-emitting diodes (<20 μm × 20 μm) exceeding 1 mW/mm2 for full-color micro-displays

  1 min read · Tue, Jul 20 2021

  News

  The paper reports InGaN-based RGB micro-LED arrays that comprise every single µLED in the dimension of 17 × 17 µm2. We obtained the output power density of the InGaN-based red µLEDs as 1.76 mW/mm2, which was estimated to be higher than that of 20 × 20 µm2 AlInGaP red µLEDs (~630 nm). The result reveals a great potential for the InGaN materials to be used in full-color micro-displays.

May 2021

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  606-nm InGaN Amber Micro-Light-Emitting Diodes With an On-Wafer External Quantum Efficiency of 0.56%

  1 min read · Thu, May 13 2021

  News

  The paper reports the device performances of the amber micro-LEDs. The on-wafer external quantum efficiency was as high as 0.56%. The micro-LEDs have recently gathered considerable interest for next-generation display applications, such as smartphones and watches, augmented reality (AR), and virtual reality (VR) devices.
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  Making the shift from blue to red for better LEDs

  1 min read · Sun, May 9 2021

  News

  materials science semiconductors electrical engineering

  Pure red-light micrometer-scale emitting devices made from a nitride semiconductor reaches excellent efficiency.

March 2021

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  Paper accepted in Optics Letters & Ranked in “Top Downloads” during April-June 2021!

  1 min read · Fri, Mar 12 2021

  News

  This paper has ranked in "Top Downloads".​ Congratulations!
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  Paper published in SPIE Conference Proceedings!

  1 min read · Fri, Mar 12 2021

  News

  The paper reports that phonon-exciton interaction properties in experimental PL spectrum analysis and theoretical calculation of population transfers of excitonic levels. [Abstract] Longitudinal optical (LO) phonon has strong electric interaction with particles and fields. Particularly, the interaction in III-nitrides is more significant than that in conventional III-V materials. We show phonon-exciton interaction properties in experimental PL spectrum analysis and theoretical calculation of population transfers of excitonic levels. Thermally nonequilibrium occupations of LO phonons and other

December 2020

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  KAUST Discovery features "Optoelectronic devices that emit warm and cool white light"

  1 min read · Mon, Dec 21 2020

  News

  material science electrical engineering

  A single semiconducting material can produce white light by emitting light across the visible spectrum.

October 2020

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  High-color-rendering-index phosphor-free InGaN-based white light-emitting diodes by carrier injection enhancement via V-pits

  1 min read · Sun, Oct 11 2020

  News

  The paper entitled "High-color-rendering-index phosphor-free InGaN-based white light-emitting diodes by carrier injection enhancement via V-pits" reports the growth of phosphor-free InGaN-based white light-emitting diodes by metalorganic vapor-phase epitaxy.​ Appl. Phys. Lett. 117, 172103 (2020).​ DOI: 10.1063/5.0026017​

May 2020

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  Pure red LEDs fulfill a primary goal

  1 min read · Wed, May 6 2020

  News

  material science electrical engineering

  First high-intensity, low-voltage red LEDs made from nitride semiconductors.