Article
Chemistry, Multidisciplinary
Tae Kyoung Kim, Abu Bashar Mohammad Hamidul Islam, Yu-Jung Cha, Seung Hyun Oh, Joon Seop Kwak
Summary: This work proposes an InGaN/GaN multiple-quantum-well flip-chip blue ultrathin side-emitting LED and improves the light extraction efficiency for increased light output power, making it suitable for backlight units.
Article
Chemistry, Multidisciplinary
Kunsik An, Chaewon Kim, Sunkuk Kim, Taesoo Lee, Dongyeol Shin, Jaemin Lim, Donghyo Hahm, Wan Ki Bae, Jun Young Kim, Jeonghun Kwak, Jaehoon Kim, Kyung-Tae Kang
Summary: This paper presents a novel light extraction structure called RaDiNa, which enhances the light extraction capability of top-emitting quantum dot light-emitting diodes (TE-QLEDs). By detaching a polydimethylsiloxane (PDMS) film from a ZnO nanorod (ZnO NR) layer and laying it on top of the TE-QLED, the RaDiNa-attached TE-QLED achieves significantly improved external quantum efficiency (EQE) compared to the reference device. This study provides essential information for the commercialization of TE-QLEDs.
Article
Chemistry, Analytical
Zhanxu Chen, Runhong Ding, Feng Wu, Wei Wan
Summary: The lattice pitch of indium-doped tin oxide (ITO) periodic nanostructures significantly affects the light extraction efficiency of LEDs, with a lattice constant of 800 nm showing an 83% increase in light extraction without degrading electrical properties. The calculated extraction efficiency using FDTD method is in good agreement with experimental measurements, indicating the lattice constant's impact on light extraction efficiency.
Article
Physics, Applied
Ah Hyun Park, Seungjae Baek, Go Bong Choi, Yoong Ahm Kim, Jinsub Lim, Tae Hoon Seo
Summary: In this study, green light emitting diodes (LEDs) with Au nanoclusters in a micro-hole patterned p-GaN layer (ANCs-MHPP) were demonstrated to have higher internal quantum efficiencies and faster decay times compared to conventional green LEDs. The remarkable opto-electronic performance of green LEDs with ANCs-MHPP is attributed to exciton-surface plasmon coupling and surface texturing effect caused by the micro-hole patterned p-GaN layer.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Do-Yeong Shin, Taehwan Kim, Ozgun Akyuz, Hilmi Volkan Demir, In-Hwan Lee
Summary: This study presents an improved efficiency design for white LEDs by integrating blue nanorod LEDs with green and red-emitting perovskite nanocrystal films. The design utilizes the localized surface plasmon effect of Ag@SiO2 nanoparticles to enhance the photoluminescence intensity of blue LEDs, while the high-power blue LED backlight improves the perovskite photoluminescence intensity. The resulting white LED with Ag@SiO2 nanoparticle-embedded nanorods demonstrates a 62% increase in photoluminescence intensity compared to planar white LEDs.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Wenwen Wu, Yue Liu, Xinping Zhang
Summary: Researchers have developed a large-area array of nanoscale organic light-emitting diodes (OLEDs) that produce amplified emission with a selected spectrum in a narrow band. These OLEDs share a common active layer that acts as a waveguide and gain channel for light-emitting signals. The periodic structure of the array allows for diffraction and confinement of the electroluminescence signal, resulting in strong spectral selectivity and amplification.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Multidisciplinary Sciences
Ah Hyun Park, Seungjae Baek, Young Won Kim, S. Chandramohan, Eun-Kyung Suh, Tae Hoon Seo
Summary: This study demonstrates the use of a defect-selective-etched (DSE) porous GaN layer as a buffer layer for InGaN/GaN LED development. The overgrown GaN epilayer on the DSE porous GaN exhibits reduced threading dislocations (TDs) and relaxation of compressive stress compared to the conventional GaN epilayer. The enhanced internal quantum efficiency of the InGaN/GaN LEDs is attributed to stress relaxation and TDs annihilation.
Article
Optics
Zhi-Yu Chen, Ru-Jian Zhang, Yu-Ping Wang, Da Yin, Yue-Feng Liu, Yan-Gang Bi, Jing Feng
Summary: In this study, a simple method is proposed to introduce spontaneously formed disordered wrinkles into organic light-emitting devices (OLEDs) in order to enhance light extraction and achieve stretchability. The wrinkled OLEDs show significant improvements in luminance and current efficiency compared to planar devices, and exhibit angle-stable electroluminescent spectra at wide viewing angles due to broadband light scattering induced by the disordered wrinkles.
Article
Physics, Applied
Mei Cui, Chenyu Guo, Zhenhai Yang, Li Chen, Yijun Dai, Houqiang Xu, Wei Guo, Jichun Ye
Summary: This paper investigates the application of conductive dielectric distributed Bragg reflectors (DBRs) in GaN-based light emitters. A conductive DBR was fabricated using the electrical breakdown technique. The optical simulations and electrical tests demonstrated its excellent performance. The conductive mechanisms were elaborated by comparing different metal electrodes. Ultimately, a conductive DBR with high reflectivity was successfully prepared.
JOURNAL OF APPLIED PHYSICS
(2022)
Review
Materials Science, Multidisciplinary
Muhammad Usman, Munaza Munsif, Urooj Mushtaq, Abdur-Rehman Anwar, Nazeer Muhammad
Summary: Efficiency issues in green light-emitting diodes are a major concern in the solid-state lighting industry. Researchers are exploring methods to address this issue by reducing inherent problems such as defect density and internal electric fields in order to improve the performance of green light-emitting diodes.
CRITICAL REVIEWS IN SOLID STATE AND MATERIALS SCIENCES
(2021)
Article
Engineering, Electrical & Electronic
Ramit Kumar Mondal, Vipul Pandey, Vijay Chatterjee, Suchandan Pal
Summary: The polarization-dependent light extraction efficiency (LEE) of AlGaN flip-chip deep ultraviolet light emitting diodes with embedded periodic photonic structure (PPS), surface PPS, and double-sided PPS configurations was studied using the 3D FDTD method. Among the configurations, the double-sided PPS showed the greatest improvement in LEE, followed by the embedded PPS configuration. The surface PPS offered the least improvement in LEE compared to the conventional deep-UV LED structure. The improvements in TE, TM, and overall LEE were found to be approximately 128.37%, 59.18%, and 99% for the double-sided PPS configuration compared to the conventional deep-UV LED.
OPTICAL AND QUANTUM ELECTRONICS
(2021)
Article
Optics
Linyu Cao, Kody Klimes, Yunlong Ji, Tyler Fleetham, Jian Li
Summary: The newly developed tetradentate Pd(ii) complex Pd3O8-P with near unity photoluminescent quantum yield has potential applications in high-brightness, long-lifetime OLED devices. Its features include high quantum efficiency, reduced efficiency roll-off, and an estimated operational half-lifetime of several million hours.
Article
Optics
Qifeng Lyu, Huaxing Jiang, Kei May Lau
Summary: The study demonstrates the first integration of monolithically integrated UV LEDs and visible-blind UV PDs on Si substrate, achieving high sensitivity and low dark current. By optimizing the structure and materials, it offers potential for various applications with high-performance UV PDs and LEDs.
Article
Optics
Zhe Zhuang, Daisuke Iida, Martin Velazquez-Rizo, Kazuhiro Ohkawa
Summary: The study introduced a method for fabricating ultra-small InGaN μLEDs, successfully realizing different shapes of green μLEDs. It was found that as the size of the μLED decreases, the series resistance and turn-on voltage increase, while the light output power density and external quantum efficiency also improve.
Article
Optics
Mingyin Zhang, Zhenhuan Tian, Xuzheng Wang, Feng Li, Qifan Zhang, Qiang Li, Yufeng Li, Feng Yun
Summary: This research demonstrates that coupling multiple quantum wells and surface plasmons can enhance the coherence of light emitted from LED wafers. The study also found that the coherence-enhanced wafer achieves anisotropic and deflective emission in micro areas and at far field.
Article
Nanoscience & Nanotechnology
Gisung Kim, Namhee Kwon, Dongho Lee, Mijoung Kim, Moonhoe Kim, Yongjei Lee, WooJong Kim, Daseul Hyeon, Bora Kim, Mun Seok Jeong, Jinpyo Hong, JungYup Yang
Summary: Recent studies have found that copper (I) thiocyanate (CuSCN) has significant potential as a hole extraction material for perovskite solar cells. However, the use of CuSCN can lead to unwanted dissociation of MAPbI(3) to PbI2, and the solvent DES can damage the surface of the perovskite layer. By increasing the molar ratio of MAI in the MAPbI(3) precursor solution, the surface damage to MAPbI(3) can be reduced and the dissociation to PbI2 can be effectively suppressed.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Review
Gastroenterology & Hepatology
Suyeon Park, Seong Ran Jeon, Hyun Gun Kim, Yunho Jung, Min-Seob Kwak, Su Young Kim, Jong Wook Kim, Seung-Joo Nam, Eun Hye Oh, Seon-Young Park, Soo-Kyung Park, Jeong-Sik Byeon, Sun-Jin Boo, Dong Hoon Baek, Soon Man Yoon, Jaeyoung Chun, Jooyoung Lee, Miyoung Choi
Summary: This systematic review and meta-analysis found that patients with 3-4 nonadvanced adenomas (NAAs) have a higher risk of metachronous advanced neoplasia (AN) compared to those with 1-2 NAAs. However, there was no significant difference in the risk of metachronous AN or colorectal cancer (CRC) between the 3-4 NAAs group and the >= 5 NAAs group. Further studies are needed to confirm the optimal surveillance colonoscopy interval for patients with 3-4 NAAs.
AMERICAN JOURNAL OF GASTROENTEROLOGY
(2022)
Article
Gastroenterology & Hepatology
Jae Hee Han, Hyun Gun Kim, Eu Mi Ahn, Suyeon Park, Seong Ran Jeon, Jae Myung Cha, Min Seob Kwak, Yunho Jung, Jeong Eun Shin, Hyun Deok Shin, Young-Seok Cho
Summary: The study found that adenoma detection rate (ADR) and other quality indicators do not fully reflect the adenoma miss rate (AMR) during colonoscopy, and the only factor influencing AMR is the number of adenomas detected during the colonoscopy.
Article
Chemistry, Physical
Jaekak Yoo, Kihyuk Yang, Byeong Wook Cho, Ki Kang Kim, Seong Chu Lim, Seung Mi Lee, Mun Seok Jeong
Summary: In this study, the phonon vibrational origin of a single sulfur-vacancy-induced Raman peak was identified as A(1)'(k) through quantum mechanical calculations. This finding is of great importance for improving the quality of transition metal dichalcogenides materials.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Byeong Geun Jeong, Chanwoo Lee, Sung Hyuk Kim, Seok Joon Yun, Dong Hyeon Kim, Juchan Lee, Dongki Lee, Ki Kang Kim, Seong Chu Lim, Mun Seok Jeong
Summary: Defect analysis in two-dimensional transition-metal dichalcogenides (TMDs) is important due to its significant impact on the optical and electrical properties of TMD. This study investigated the influence of sulfur vacancies and oxygen substitution on the optical properties of WS2 using laser irradiation technique. The defect-induced photoluminescence (PL) exhibited distinct features depending on the type of defects, resulting in changes in the intensities and peak positions of excitons, biexcitons, and defect-bound excitons. Defect-activated Raman modes provided information about the defects and revealed the origin of the alteration in PL.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Nanoscience & Nanotechnology
Bora Kim, Moonhoe Kim, Hyojung Kim, Sohee Jeong, JungYup Yang, Mun Seok Jeong
Summary: Perovskite solar cells (PSCs) have short lifetimes, but by using transition metal dichalcogenide (TMD) interlayers, both efficiency and stability of the devices can be improved.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Phuong Huyen Nguyen, Duc Hieu Nguyen, Donghyoung Kim, Mun Kyoung Kim, Jiseong Jang, Woo Hyeong Sim, Hyung Mo Jeong, Gon Namkoong, Mun Seok Jeong
Summary: This study investigates the regeneration of oxidized titanium carbide (Ti3C2Tx) through hydrofluoric acid (HF) post-treatment. The research reveals that the post-treatment can restore the structure and surface composition of MXene nanosheets, thereby improving their electrical conductivity and prolonging their conductivity maintenance time. This finding is crucial for the rational design of Ti3C2Tx-based devices and functional coatings.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Hwi Je Woo, Sangmin Ji, Jaewon Han, Seongwon Woo, Hyuntae Kim, Seonyeong Kim, Chang-Won Lee, Soobong Choi, Deok-Soo Kim, Mun Seok Jeong, Euyheon Hwang, Byungkwon Lim, Young Jae Song
Summary: We used scattering-type near-field scanning optical microscopy (s-NSOM) to observe optical phenomena on mono-crystalline silver nanoflakes. The momentum of tip-launched surface plasmon polaritons (SPPs) was successfully identified and showed good agreement with analytical calculations.
ACS APPLIED NANO MATERIALS
(2023)
Review
Gastroenterology & Hepatology
Han Hee Lee, Jin Su Kim, Hyeon Jeong Goong, Shin Hee Lee, Eun Hye Oh, Jihye Park, Min Cheol Kim, Kwangwoo Nam, Young Joo Yang, Tae Jun Kim, Seung-Joo Nam, Hee Seok Moon, Jae Hyun Kim, Duk Hwan Kim, Seong-Eun Kim, Seong Ran Jeon, Seung-Jae Myung
Summary: The introduction of device-assisted enteroscopy (DAE) has revolutionized the diagnosis and treatment of small intestine diseases. It provides detailed observation, tissue acquisition, and therapeutic intervention advantages compared to capsule endoscopy. To meet the increasing demand, the Korean Association for the Study of Intestinal Diseases has developed an expert consensus statement on DAE, focusing on indications, insertion route, therapeutic intervention, complications, and technical points.
KOREAN JOURNAL OF GASTROENTEROLOGY
(2023)
Article
Gastroenterology & Hepatology
Ji Hee Song, Seong Ran Jeon, Jin Su Kim, Bo-In Lee, Jin-Oh Kim, Han Hee Lee
Summary: A retrospective study showed that non-ERCP balloon-assisted enteroscopy (BAE) is an effective and safe method for patients with surgically altered gastrointestinal (GI) tract anatomy, with high technical success rate and diagnostic and therapeutic yields.
DIGESTIVE DISEASES AND SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Seung-Jae Lee, Seong Ran Jeon, Sung Hoon Jung, Young-Jun Choi, Hae-Gon Oh, Hae-Yong Lee, Min-Ki Kwon, Soon-Ku Hong
Summary: The characteristics of AlN epilayers grown directly on hole-type patterned sapphire substrate (HPSS) by hydride vapor-phase epitaxy (HVPE) are reported. The threading dislocation densities (TDDs) of AlN films grown simultaneously on HPSS and flat sapphire substrate (FSS) are analyzed by transmission electron microscopy. The results show that the TDD of AlN grown on HPSS is significantly lower than that on FSS.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Engineering, Electrical & Electronic
Wonchae Jeong, Taeyoung Kim, Yoonsok Kim, Mun Seok Jeong, Eun Kyu Kim
Summary: We demonstrate area-selective doping of MoS2 field-effect transistors using 1,2-dichloroethane (DCE) solution. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy measurements confirm the blocked layer (BL) using a photoresist, which suppresses the doping effect of the DCE treatment. Electrical measurements confirm the enhancement in field-effect mobility and subthreshold swing after area-selective doping.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2023)
Editorial Material
Gastroenterology & Hepatology
Seong Ran Jeon
KOREAN JOURNAL OF GASTROENTEROLOGY
(2023)
Article
Materials Science, Multidisciplinary
Geunchang Choi, Dong-Hwan Choi, Junho Ryeom, Dae Young, Wu-Sin Kim, Ju-Jin Kim, Young-Mi Bahk, Mun Seok Jeong
Summary: High-quality indium thin films were fabricated by substrate cooling method, reducing the threshold thickness for insulator-to-metal transition. The films' complex conductivities were measured by terahertz time-domain spectroscopy, showing that the conductivity of the cooled indium films was 10 times higher than that deposited at room temperature, despite their lower thickness. These results suggest the promising applications of substrate cooling in metal thin films and contacts.
CURRENT APPLIED PHYSICS
(2023)
Article
Automation & Control Systems
Jaekak Yoo, Youngwoo Cho, Byeonggeun Jeong, Soo Ho Choi, Ki Kang Kim, Seong Chu Lim, Seung Mi Lee, Jaegul Choo, Mun Seok Jeong
Summary: The application of explainable artificial intelligence in nanomaterial research has facilitated the discovery of novel physical findings. In this study, the correlation between light scattering and emission in a WSe2 monolayer is investigated by bridging explainable artificial intelligence and quantum mechanical calculations. Convolutional neural networks are trained using light scattering and emission data to determine the relationships between them. The findings are independently evaluated through quantum mechanical calculations, providing reliable fundamental physical insight and suggesting a novel methodology for materials science.
ADVANCED INTELLIGENT SYSTEMS
(2023)
