Article
Physics, Applied
Panpan Li, Haojun Zhang, Hongjian Li, Trevor Cohen, Ryan Anderson, Matthew S. Wong, Emily Trageser, Yi Chao Chow, Mattanjah de Vries, Shuji Nakamura, Steven P. DenBaars
Summary: We demonstrate room-temperature stimulated emission at 568 nm from low dislocation density InGaN/GaN multi-quantum wells. For a 1.4 mm long and a 50 mu m wide ridge bar optically pumped by a high-power pulsed laser, we observed an emission peak at 568 nm with a narrow spectral width of less than 2 nm at room temperature. The measured pumping threshold is less than 1.5 MW/cm(2), and the polarization ratio of the emission is over 90%. This demonstration paves the way for the future development of electrically injected InGaN semiconductor yellow laser diodes.
APPLIED PHYSICS LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Jumpei Yamada, Ai Mizuno, Tatsuya Honda, Keigo Yoshida, Rie Togashi, Ichirou Nomura, Tomohiro Yamaguchi, Tohru Honda, Katsumi Kishino
Summary: This study investigated the growth behavior of Indium gallium nitride (InGaN)-based nanocolumn arrays and fabricated red emission nanocolumn micro-light emitting diodes (μ-LEDs). The internal structure of the InGaN/GaN superlattice (SL) layer under the multiple-quantum-well (MQW) active layers was evaluated using scanning transmission electron microscopy (STEM) analysis. It was found that the crystal plane at the top of the nanocolumn changed as the number of SL pairs increased, and the growth of the semipolar (10-11) plane InGaN active layers was observed. Red nanocolumn μ-LEDs with an φ12μm emission window were fabricated, achieving an external quantum efficiency of 1.01% at 51 A cm(-2).
Article
Physics, Applied
Takao Oto, Aoto Aihara, Kai Motoyama, Shunsuke Ishizawa, Koichi Okamoto, Rie Togashi, Katsumi Kishino
Summary: By using ordered fine nanocolumns, emission enhancement based on surface plasmon polariton (SPP) coupling was achieved. The honeycomb lattice allowed for a longer SPP resonant wavelength in the red region compared to the triangular lattice. The red-emission nanocolumn system demonstrated effective synergy between plasmonic and nanocrystalline effects. Additionally, light-extraction enhancement was achieved by introducing plasmonic crystals (PlCs) and metal reflection, changing the emission directionality.
APPLIED PHYSICS EXPRESS
(2023)
Article
Chemistry, Multidisciplinary
Chaoqiang Zhang, Ke Gao, Fei Wang, Zhiming Chen, Philip Shields, Sean Lee, Yanqin Wang, Dongyan Zhang, Hongwei Liu, Pingjuan Niu
Summary: This paper investigates the edge strain relaxation of InGaN/GaN MQW micro-pillars. The results show a significant peak wavelength shift between micro-pillar arrays caused by a high range of strain relaxation. Raman spectrum observation and finite element method simulation provide effective verification of the strain relaxation analysis, offering references for the design and analysis of small-size micro-LED devices.
APPLIED SCIENCES-BASEL
(2022)
Article
Physics, Applied
Takao Oto, Masato Namazuta, Shotaro Hayakawa, Koichi Okamoto, Rie Togashi, Katsumi Kishino
Summary: The study found that using Ag and Au-based plasmonic crystals (PlCs) in InGaN/GaN nanocolumn arrays can enhance light emission, with resonance occurring in the visible light region. Calculations showed that the SPP resonance wavelength in Ag-based NC-PlCs can be controlled, leading to stronger electric field intensity over a wide range of wavelengths.
APPLIED PHYSICS EXPRESS
(2021)
Article
Engineering, Electrical & Electronic
Marco Nicoletto, Alessandro Caria, Carlo De Santi, Matteo Buffolo, Xuanqui Huang, Houqiang Fu, Hong Chen, Yuji Zhao, Gaudenzio Meneghesso, Enrico Zanoni, Matteo Meneghini
Summary: In this article, we extensively investigate the degradation of gallium nitride (GaN)-based high periodicity indium GaN (InGaN)-GaN multiple quantum well (MQW) solar cells under optical stress at high excitation intensity and high temperature. The obtained results suggest that the degradation originates from the diffusion of hydrogen, and the proposed analytical methodology provides insight into MQW solar cell degradation.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Optics
Yuchen Suo, Xinda Song, Zhendong Wu, Ziqi Yuan, Le Jia, Tengyue Long
Summary: We propose a miniaturized single-beam optically pumped magnetometer (OPM) with a laser power differential structure, along with a dynamically-adjusted detection circuit, which enables the suppression of optical fluctuation noise and the enhancement of magnetometer sensitivity.
Article
Nanoscience & Nanotechnology
K. Kluczyk-Korch, D. Palazzo, A. Waag, A. Dieguez, J. D. Prades, A. Di Carlo, M. Auf der Maur
Summary: This research aims to overcome the spatial resolution limitations of optical systems by developing a spatially resolved light source based on semiconductor nanoLED arrays. Through optical simulations and theoretical analysis, the study explores the design of GaN nanofins and nanorods arrays, finding that suitable array dimensions can improve light output directionality and concentration, potentially leading to chip-based superresolution microscopy with enhanced spatial resolution.
Article
Nanoscience & Nanotechnology
Meixin Feng, Hanru Zhao, Rui Zhou, Yongjun Tang, Jianxun Liu, Xiujian Sun, Qian Sun, Hui Yang
Summary: GaN-based microdisk laser monolithically integrated on Si(100) with lower junction temperature and narrow spectral line width was successfully fabricated using wafer bonding and substrate removal.
Article
Chemistry, Multidisciplinary
Nima Taghipour, Ibrahim Tanriover, Mariona Dalmases, Guy L. Whitworth, Christina Graham, Avijit Saha, Onur Ozdemir, Biswajit Kundu, Valerio Pruneri, Koray Aydin, Gerasimos Konstantatos
Summary: This study demonstrates the potential of colloidal semiconductor quantum dots (QDs) for solution-processed laser diodes by using a binary blend of QDs and ZnO nanocrystals. The study also shows the observation of infrared amplified spontaneous emission and stimulated emission, suggesting a promising device for realizing infrared QD-based laser diodes.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Dae-Young Um, Yong-Ho Ra, Ji-Hyeon Park, Ga-Eun Hong, Cheul-Ro Lee
Summary: This study presents a new approach to incorporate high concentrations of indium in the InGaN structure using a non-polar quasi-quantum dot heterostructure. The results show that this method can not only improve the radiative recombination efficiency of the nanowire structure, but also enhance the crystalline quality, allowing quantum dots to shift the wavelength up to 913 nm. The integration of nanowire and quantum dot structures opens a new avenue to overcome the limitations of high indium incorporation in photonic semiconductor systems.
NANOSCALE ADVANCES
(2021)
Article
Optics
Zixin Yang, Syde Zaheer Ud Din, Pengchao Wang, Chun Li, Zhiwei Lin, Jiancai Leng, Jie Liu, Lin Xu, Qi Yang, Xianghe Ren
Summary: We report the generation of high energy visible pulsed beam from a blue LD-pumped electro-optically Q-switched Pr:YLF laser for the first time. Through optimization of experimental conditions, we obtained the shortest pulse duration and highest peak power at a repetition rate of 100 Hz, demonstrating excellent performance.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Computer Science, Information Systems
Katarzyna Kluczyk-Korch, Sergio Moreno, Joan Canals, Angel Dieguez, Jan Gulink, Jana Hartmann, Andreas Waag, Aldo Di Carlo, Matthias Auf Der Maur
Summary: GaN-based LEDs have demonstrated efficient operation at nanoscale, enabling the downsizing of chip-based LED display technology. Two approaches to achieving individually switchable nano-LED arrays were evaluated using simulations and compared with performance data from fabricated arrays. The study highlights the impact of LED array geometry and materials on the final illumination spot size and shape.
Article
Optics
Hui Zi, Yuk Fai Cheung, Benjamin Damilano, Eric Frayssinet, Blandine Alloing, Jean-Yves Duboz, Philippe Boucaud, Fabrice Semond, Hoi Wai Choi
Summary: Optically pumped whispering-gallery mode (WGM) lasing is observed from a thin-film GaN microdisk processed from GaN-on-Si InGaN/GaN multi-quantum well wafers by selective wet-etch removal of the substrate. The surface smoothness of the microdisk is significantly improved compared to those processed from GaN-on-sapphire wafers through laser lift-off. The improved surface smoothness contributes to superior optical confinement and better lasing performance.
Article
Optics
Martin Fibrich, Jan Sulc, Richard Svejkar, Helena Jelinkova
Summary: This study has successfully demonstrated the first continuous-wave quasi three-level laser emitting in the cyan-blue spectral range in praseodymium-doped oxide materials, achieving a high output power and efficiency.
APPLIED PHYSICS B-LASERS AND OPTICS
(2021)