Review
Chemistry, Analytical
Federica Mariani, Isacco Gualandi, Wolfgang Schuhmann, Erika Scavetta
Summary: Electrode miniaturization has revolutionized electrochemical sensing, allowing for high-resolution probing of biological events, integration with microfluidics, and design of multiplexed sensing arrays. Despite the advancements, there is still room for improvement in lab-on-a-chip devices, brain chemistry, and cell monitoring.
Article
Physics, Applied
Byung-Ju Min, Yeon-Ji Kim, Jae-Hyuck Choi, Min-Woo Kim, Kyong-Tae Park, Dong Jin Jang, Jin Sik Choi, You-Shin No
Summary: This study demonstrates the electrically driven on-chip transferrable microdisk light-emitting diodes (LEDs). By using multilayered graphene sheets as contacts, single micro-LEDs are fabricated and transferred onto a chip. The characterization of the fabricated micro-LEDs shows diode-like transport behaviors and polarization-resolved emission properties. This research contributes to the electrification of on-chip microarchitectures.
APPLIED PHYSICS LETTERS
(2022)
Review
Chemistry, Analytical
Youwei Zhang, Ruiqiang Xu, Qiushi Kang, Xiaoli Zhang, Zi-hui Zhang
Summary: This paper reviews the reasons for the low external quantum efficiency (EQE) of micro LEDs and introduces optimization techniques to improve the EQE of micro LEDs.
Article
Optics
Yaozheng Wu, Bin Liu, Feifan Xu, Yimeng Sang, Tao Tao, Zili Xie, Ke Wang, Xiangqian Xiu, Peng Chen, Dunjun Chen, Hai Lu, Rong Zhang, Youdou Zheng
Summary: Hybrid p-i-n tunnel junction (TJ) contacts were fabricated for hole injection on c-plane green micro-light-emitting diodes (micro-LEDs) using a combination of plasma-assisted molecular beam epitaxy (PA-MBE) and metal organic chemical vapor deposition (MOCVD). The TJ structure allowed for a steep doping interface and ultrathin depletion width, leading to reduced device resistance, enhanced electroluminescence intensity, and decreased efficiency droop in comparison to standard micro-LEDs. The size-independent J-V characteristics suggested that TJ could serve as an excellent current spreading layer.
PHOTONICS RESEARCH
(2021)
Article
Physics, Applied
Jinpeng Huang, Minglei Tang, Binru Zhou, Zhiqiang Liu, Xiaoyan Yi, Junxi Wang, Jinmin Li, Anlian Pan, Liancheng Wang
Summary: Augmented reality is a next-generation interactive display that enhances user interaction with digital content and the real world. The use of micro-LEDs in AR has some limitations, but this study successfully incorporates distributed Bragg reflectors into micro-LEDs to improve their optical characteristics, making them suitable for various AR applications.
APPLIED PHYSICS LETTERS
(2022)
Article
Optics
Pengjiang Qiu, Shijie Zhu, Zuxin Jin, Xiaolin Zhou, Xugao Cui, Pengfei Tian
Summary: This Letter proposes a high-speed optical wireless communication system based on LEDs and micro-LEDs, achieving simultaneous visible light communication and UV communication using wavelength division multiplexing technology. The system achieves high data transmission rates and demonstrates the advantages and potential of micro-LEDs in optical wireless communication.
Article
Chemistry, Multidisciplinary
Yu-Chung Lin, Ikai Lo, Cheng-Da Tsai, Ying-Chieh Wang, Hui-Chun Huang, Chu-An Li, Mitch M. C. Chou, Ting-Chang Chang
Summary: Red, green, and blue lighting micro-LEDs can be fabricated using InxGa1-xN multiple quantum wells grown on GaN/γ-LiAlO2 microdisk substrates. Optimization of self-assembly growth of InxGa1-xN multiple quantum well microdisks using a ball-stick model has been achieved through bottom-up nanotechnology. It has also been demonstrated that a beautiful InxGa1-xN-QW microdisk for optoelectronic applications can be fabricated by selecting an appropriate buffer layer.
Article
Engineering, Electrical & Electronic
Xinyi Shan, Guobin Wang, Shijie Zhu, Pengjiang Qiu, Runze Lin, Zhou Wang, Zexing Yuan, Qi-ang Yan, Xugao Cui, Jianfeng Wang, Wengang Bi, Ran Liu, Ke Xu, Pengfei Tian
Summary: This study demonstrated a 20µm blue micro-LED fabricated on a 2-inch c-plane GaN freestanding substrate with high bandwidth over 1 GHz. Systematic comparisons were conducted with sapphire-substrate micro-LED, and the GaN-substrate micro-LED showed superior optoelectronic properties and communication performance due to its lower threading dislocation density and better heat dissipation.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Physics, Applied
Jinpeng Huang, Yi Xu, Binru Zhou, Huming Zhan, Peng Cao, Junxi Wang, Jinmin Li, Xiaoyan Yi, Anlian Pan, Liancheng Wang
Summary: 3D micro-LED displays combine the characteristics of 3D display and the advantages of micro-LEDs, providing users with a 3D experience. LP micro-LEDs with varied chip diameters are investigated and show potential for use in 3D micro-LED displays.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Shaogang Liu, Sancan Han, Chenchao Xu, Huiwen Xu, Xianying Wang, Ding Wang, Yuankun Zhu
Summary: Micro-LEDs, as a new display technology, have advantages such as low power consumption, high brightness, high resolution, and fast response time, but their efficiency is reduced by strong surface non-radiative recombination. In this study, an ion implantation method was used to improve the luminous efficiency of GaN-based Micro-LEDs by inhibiting carrier surface non-radiative recombination, resulting in a 7-fold increase in photoluminescence intensity and a 33% increase in external quantum efficiency of the packaged Micro-LEDs chip. This research provides a new direction for improving the photoelectric performance of Micro-LEDs.
Article
Chemistry, Physical
In-Hwan Lee, Tae-Hwan Kim, A. Y. Polyakov, A. V. Chernykh, M. L. Skorikov, E. B. Yakimov, L. A. Alexanyan, I. V. Shchemerov, A. A. Vasilev, S. J. Pearton
Summary: In this study, a matrix of blue GaN/InGaN multi-quantum-well micro-LEDs was prepared and characterized. The changes in photoluminescence and microcathodoluminescence spectra were found to be related to the formation of deep hole traps and electron traps in the sidewalls of the micro-LEDs.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Review
Materials Science, Multidisciplinary
Yanfen Gong, Zheng Gong
Summary: This paper systematically reviews and analyzes the main challenges and technical solutions in Micro-LED displays, focusing on laser manufacturing processes. The fundamental principles and mechanisms of laser manufacturing processes are discussed, along with a detailed analysis of their advantages and disadvantages. The future research directions of laser techniques in Micro-LED display are also explored.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Optics
A. Pandey, Y. Malhotra, P. Wang, K. Sun, X. Liu, Z. Mi
Summary: This paper demonstrates the performance of N-polar InGaN/GaN nanowire sub-microscale red light emitting diodes (LEDs) for the first time. These LEDs exhibit higher efficiency and brightness compared to conventional red-emitting micro-LEDs. In-situ annealing significantly enhances the optical emission intensity, and the fabricated LED sizes are extremely small.
PHOTONICS RESEARCH
(2022)
Article
Optics
Xianhe Liu, Yi Sun, Yakshita Malhotra, Ayush Pandey, Ping Wang, Yuanpeng Wu, Kai Sun, Zetian Mi
Summary: This study addresses the issue of efficiency reduction in conventional quantum well light-emitting diodes (LEDs) with reduced areal size by utilizing N-polar InGaN nanowires. The epitaxy and performance characteristics of N-polar InGaN nanowire LEDs were studied, achieving a maximum external quantum efficiency of around 11% for LEDs with lateral dimensions as small as 750 nm directly on wafer without any packaging. The impact of electron overflow and Auger recombination on device performance was also investigated.
PHOTONICS RESEARCH
(2022)
Article
Nanoscience & Nanotechnology
Sae Katsuro, Weifang Lu, Kazuma Ito, Nanami Nakayama, Shiori Yamamura, Yukimi Jinno, Soma Inaba, Ayaka Shima, Naoki Sone, Dong-Pyo Han, Kai Huang, Motoaki Iwaya, Tetsuya Takeuchi, Satoshi Kamiyama
Summary: This study investigates the improvement of optical properties and the realization of micro-LEDs by removing the (0001) plane region in GaInN/GaN MQS NWs. The results show that the EL intensity can be enhanced by removing the (0001) plane region, and the light output of truncated samples can be increased for more than ten times compared to the samples without (0001) plane etching.
Article
Chemistry, Multidisciplinary
Hongqiang Li, Zhixuan An, Quanhua Mao, Shasha Zuo, Wei Zhu, Shanshan Zhang, Cheng Zhang, Enbang Li, Juan Daniel Prades Garcia
Summary: A waveguide Bragg grating (WBG) has been designed for temperature measurement, with two-sided WBG showing the ability to measure temperature changes within the range of 35-42 degrees Celsius with a measurement error of 0.1 degrees Celsius. This approach has the potential for application in wearable technology and human temperature measurement.
Article
Chemistry, Analytical
Olga Qomaruddin, Olga Casals, Hutomo Suryo Wasisto, Andreas Waag, Joan Daniel Prades, Cristian Fabrega
Summary: This work presents nitrogen dioxide (NO2) gas sensors based on zinc oxide nanorods (ZnO NRs) decorated with gold nanoparticles (Au NPs) that function under visible-light illumination. The study demonstrates the contribution of localized surface plasmon resonant (LSPR) by Au NPs attached to ZnO NRs. The presence of LSPR extends the functionality of ZnO NRs and increases the response at different wavelengths.
Article
Chemistry, Inorganic & Nuclear
Kuda Feke, Melisew Tadele Alula, Hendrik Spende, Andreas Waag, Peter Lemmens
Summary: In this study, CuS/Fe3O4 composite structures were prepared using a two-step process and demonstrated oxidase-like activity for the colorimetric determination of chromium (VI). The method showed a low detection limit and a wide linear dynamic range, as well as high selectivity against interference cations and anions.
JOURNAL OF CLUSTER SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Lukas Peters, Christoph Margenfeld, Jan Krugener, Carsten Ronning, Andreas Waag
Summary: The presence of carbon impurities in AlN was believed to be the main cause of the absorption at 265 nm. However, this study revealed that the intrinsic nitrogen-vacancy defect V-N plays a crucial role in the absorption. This finding is significant for further improvement of UV-LEDs.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Irene Manglano Clavero, Christoph Margenfeld, Jana Hartmann, Andreas Waag
Summary: This study investigates the influence of temperature and ammonia partial pressure on the morphology of GaN shell grown on GaN microfin cores. It is shown that growth above 1000 degrees C is determined by the competition between growth and decomposition, leading to material redistribution between different surfaces. Decomposition processes are found to strongly influence the vertical-to-lateral distribution of material during GaN growth on 3D structures. The findings emphasize the importance of understanding thermal decomposition processes and material redistribution for controlling and optimizing growth on these architectures.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Computer Science, Artificial Intelligence
Ismael Benito-Altamirano, David Martinez-Carpena, Olga Casals, Cristian Fabrega, Andreas Waag, Joan Daniel Prades
Summary: This article presents a method of using QR Codes as color correction charts in digital photography, achieving more accurate color correction schemes by preserving the original QR Code functionality and utilizing the capabilities of CRC codes.
PATTERN RECOGNITION
(2023)
Article
Multidisciplinary Sciences
Ismael Benito-Altamirano, David Martinez-Carpena, Olga Casals, Cristian Fabrega, Andreas Waag, Joan Daniel Prades
Summary: This article introduces the application and research of color QR Codes. Thousands of QR Codes images were generated using different algorithms and variables, and the signal-to-noise ratio and bit error rate were calculated. The reading performance of a commercial QR Code scanner was also tested.
Article
Physics, Applied
Lukas Peters, Dmitry Sergeev, Christoph Margenfeld, Michael Mueller, Andreas Waag
Summary: High-temperature annealing is a promising technique for producing high-quality AlN templates, but its yield is limited due to contamination on the template surface when using the face-to-face configuration. Open-face annealing leads to excessive AlN evaporation and surface degradation. By studying AlN sublimation behavior at typical HTA conditions, the limiting factors of the open-face approach can be identified.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Lukas Peters, Hendrik Spende, Stefan Wolter, Christoph Margenfeld, Carsten Ronning, Tobias Voss, Andreas Waag
Summary: In this study, carbon-implanted and high-temperature annealed AlN layers were analyzed using cathodoluminescence spectroscopy. Donor-acceptor pair transitions between carbon and oxygen impurities were identified. The presence of oxygen led to absorption in the deep UV range, while carbon was responsible for an absorption band at around 265 nm. The findings were supported by temperature- and power-dependent emission energy shifts and luminescence transients.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Falihah Balqis, Calvin Eldona, Basuki Tri Laksono, Quratul Aini, Faiq Haidar Hamid, Hutomo Suryo Wasisto, Afriyanti Sumboja
Summary: Silicon anode has a high theoretical specific capacity, but its suitability in lithium-ion batteries is limited by problems associated with volume changes and low electrical conductivity. Conductive polymer frameworks have emerged as a solution to enhance anode performance by facilitating charge transport and regulating volume changes. This review provides a detailed summary of the features of conductive polymer frameworks in silicon anodes and discusses the current advancements of widely used conductive polymers. The performance evaluation of silicon anodes with different conductive polymers is also presented, along with perspectives on future challenges.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Food Science & Technology
Linda Ardita Putri, Iman Rahman, Mayumi Puspita, Shidiq Nur Hidayat, Agus Budi Dharmawan, Aditya Rianjanu, Sunu Wibirama, Roto Roto, Kuwat Triyana, Hutomo Suryo Wasisto
Summary: We developed and evaluated a portable electronic nose (e-nose) for sniffing and classifying different meat floss products. The e-nose showed promising results in food authenticity testing and could help detect deception and food fraud attempts.
NPJ SCIENCE OF FOOD
(2023)
Article
Optics
Alessia Di Vito, Peyman Amiri, Steffen Bornemann, Georg Schottler, Maximilian Vergin, Florian Meierhofer, Jan Guelink, Andreas Waag, Joan Canals, Angel Dieguez, J. Daniel Prades, Matthias Auf Der Maur
Summary: The design study presents a micro illumination tool based on GaN microLED arrays. By optimizing the structural parameters, the extraction efficiency and spatial resolution of the resulting light patterns are improved. Adding an In-GaN micro-lens array achieves the best performance.
Article
Acoustics
Sebastian Anzinger, Christian Bretthauer, Hutomo Suryo Wasisto, Alfons Dehe
Summary: This work presents novel airborne capacitive micromachined ultrasonic transducers (CMUTs) based on dual-backplate (DBP) technology. These transducers, unlike conventional CMUTs, employ a three-electrode capacitive system, enabling larger displacement amplitudes and wide adjustable bandwidth. The fabricated DBP-CMUT prototypes demonstrate high receive and transmit sensitivities, making them suitable for airborne ranging applications.
IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
(2023)
Article
Multidisciplinary Sciences
Sebastian Junge, Maria Elena Ricci Signorini, Masa Al Masri, Jan Guelink, Heiko Bruening, Leon Kasperek, Monika Szepes, Mine Bakar, Ina Gruh, Alexander Heisterkamp, Maria Leilani Torres-Mapa
Summary: This study explores the use of optogenetics to address questions in cardiac research by controlling light. A micro-LED array is incorporated into a fluorescence microscope for controlled light stimulation of cardiac cells and tissues. By applying different patterns of light, calcium waves in cardiac tissues were successfully controlled.
SCIENTIFIC REPORTS
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Victor Moro, Nil Franch, Joan Canals, Juan Daniel Prades, Georg Schoettler, Steffen Bornemann, Andreas Waag, Angel Dieguez
Summary: GaN technology has revolutionized the field of light emitting sources, opening up new research opportunities. The integration of GaN-on-Si microdisplays has enabled the development of highly efficient visible light communication devices and image applications. This work presents an in-pixel driving circuit with high brightness and high-speed capabilities, addressing the leakage issues of conventional drivers.
PROCEEDINGS OF THE 37TH CONFERENCE ON DESIGN OF CIRCUITS AND INTEGRATED SYSTEMS (DCIS 2022)
(2022)