Article
Chemistry, Multidisciplinary
Junyi Zhao, Li-Wei Lo, Haochuan Wan, Pengsu Mao, Zhibin Yu, Chuan Wang
Summary: A method for manufacturing perovskite LEDs (PeLEDs) directly on an elastomer substrate using inkjet printing process is reported in this study, significantly reducing the fabrication time. The printed PeLEDs have a novel structure and exhibit excellent performance.
ADVANCED MATERIALS
(2021)
Article
Multidisciplinary Sciences
Jin-Hoon Kim, Jin-Woo Park
Summary: An intrinsically stretchable organic light-emitting diode, made of highly stretchable constituent materials, is able to emit light under strains as large as 80%. It has a low turn-on voltage of 8 V and a maximum luminance of 4400 cd m(-2) from both the anode and cathode sides. The device can withstand repeated stretching cycles up to 200 times and shows improved light-emitting efficiency with small stretches up to 50%.
Article
Optics
Bo -Yen Lin, Ya-Xun Lin, Shao-Ju Lin, Yi-Yen Lin, Su-Hua Chen, Mao-Kuo Wei
Summary: The use of self-assembly microlens array films (MAFs) made of silica microspheres and acrylic resin significantly improves the light extraction efficiency (LEE) and angular-spectrum stability of organic light emitting diodes (OLEDs). The MAFs, fabricated through a simple and cost-effective spin-coating process, have a high fill factor of 71.42% and exhibit high transmittance (86.2-90.6%) and high haze (78.9-82.4%) in the UV-Vis regime. The incorporation of MAFs enhances the external quantum efficiency (EQE) of OLEDs by 66% compared to reference OLEDs, while maintaining a small angular shift of CIE-indices and a wide viewing angle range.
JOURNAL OF LUMINESCENCE
(2023)
Article
Chemistry, Multidisciplinary
Xiangyu Fu, Yash Mehta, Yi-An Chen, Lei Lei, Liping Zhu, Nilesh Barange, Qi Dong, Shichen Yin, Juliana Mendes, Siliang He, Renuka Gogusetti, Chih-Hao Chang, Franky So
Summary: The study demonstrates highly directional and polarized light emission from LEDs by selectively diffracting the TE waveguide mode, showing potential for more efficient photonic applications.
ADVANCED MATERIALS
(2021)
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
Optics
Chadwick L. Canedy, William W. Bewley, Stephanie Tomasulo, Chul Soo Kim, Charles D. Merritt, Igor Vurgaftman, Jerry R. Meyer, Mijin Kim, Thomas J. Rotter, Ganesh Balakrishnan, Terry D. Golding
Summary: The study demonstrates the high-quality growth of interband cascade light emitting devices (ICLEDs) on silicon substrates, showing good performance and manufacturing advantages. Despite some leakage current issues with the silicon devices, the efficiency at high continuous wave current remains at 75% of devices grown on GaSb.
Article
Chemistry, Multidisciplinary
Eun-Jeong Bae, Shin-Woo Kang, Geun-Su Choi, Eun-Bi Jang, Dong-Hyun Baek, Byeong-Kwon Ju, Young-Wook Park
Summary: In this study, a micro-nano hybrid structure for the external light extraction layer was applied to enhance the efficiency of extracting external light from OLEDs. The micro-nano hybrid structure was formed through the reactive ion etching process using O-2 and CHF3 plasma. Experimental and theoretical analyses were conducted to compare the efficiency of different structures. The results showed that the application of the micro-nano hybrid structure improved the external light extraction efficiency by up to 38% and expanded the viewing angle profile of OLEDs. Furthermore, an effective method for enhancing the out-coupling efficiency of OLEDs was proposed by optimizing the micro-nano hybrid structure according to process conditions.
Article
Chemistry, Multidisciplinary
Shu-Jen Wang, Anton Kirch, Michael Sawatzki, Tim Achenbach, Hans Kleemann, Sebastian Reineke, Karl Leo
Summary: Conventional organic optoelectronic devices have low carrier mobility due to disorder. This study presents monolithic integrated triclinic crystal rubrene light-emitting diodes (LEDs) with engineered functional additives. The crystalline LEDs show superior charge transport, operational stability, and long-term stability. However, the crystalline phase reduces the overall performance compared to amorphous rubrene in terms of exciton dynamics and annihilation rates. The potential applications of rubrene and/or its derivatives crystalline films for improving the performance of organic and hybrid optoelectronic devices are discussed.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Eun-Jeong Bae, Hyeong-Kyu Maeng, Ji-Soo Shin, Dong-Wook Park, Young-Wook Park, Dong-Hyun Baek
Summary: A micro-sphere PDMS film is proposed to improve the external quantum efficiency (EQE) in OLEDs. The film is fabricated through a specific process and the size and distribution of the micro-spheres play essential roles in improving the performance. Additionally, the film, based on polymeric materials, offers advantages in cost control and large-scale production.
Article
Engineering, Electrical & Electronic
Feisong Qin, Min Lu, Siqi Sun, Po Lu, Nannan Feng, Yanbo Gao, Xue Bai, Zhennan Wu, Junhua Hu, Yu Zhang
Summary: Introduces the use of PMMA modified printing paper as substrates for highly flexible red-emitting perovskite light emitting diodes (PeLEDs), which have easy synthesis and excellent optoelectronic properties. This extension of technology widens the opportunity of PeLEDs in extremely flexible and inexpensive applications.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Sanmun Kim, Jeong Min Shin, Jaeho Lee, Chanhyung Park, Songju Lee, Juho Park, Dongjin Seo, Sehong Park, Chan Y. Park, Min Seok Jang
Summary: This paper introduces a method using artificial neural networks to predict the light extraction efficiency of organic LED structures and demonstrates the effectiveness in solving inverse problems. By combining neural networks with conventional genetic algorithms, additional large-scale optimization problems such as maximizing light extraction efficiency and minimizing angle dependent color shift are addressed, establishing a platform for tackling computation-heavy optimization tasks.
Article
Multidisciplinary Sciences
Tinh Binh Tran, Feras AlQatari, Quang-Ho Luc
Summary: A new method was developed to create a random nanophotonic crystal structure on a sapphire substrate without photolithography, which has the potential to enhance the light-extraction efficiency of deep ultraviolet light-emitting diodes. Simulations showed that integrating this NPhC significantly improved the LEE of DUV-LED devices compared to conventional ones.
SCIENTIFIC REPORTS
(2021)
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
Materials Science, Multidisciplinary
Li-Yin Chen, Kun-Min Hsieh, Yi-Ju Wu, Chung-An Hsieh, Jin-Kai Chang, De-Hui Liu, Hsiao-Wen Hung, Shu-Yi Ho, Chih-Hao Chang
Summary: A novel phosphor doped glass substrate has been developed to simplify device structures of WOLED, achieving high-quality white light for lighting applications. The WOLED exhibits low turn-on voltage, high power efficiency, and external quantum efficiency, suitable for high-quality solid-state lighting in daily life.
ORGANIC ELECTRONICS
(2021)
Article
Chemistry, Multidisciplinary
Eun-Jeong Bae, Yeon-Sik Kim, Geun-Su Choi, Byeong-Kwon Ju, Dong-hyun Baek, Young-Wook Park
Summary: In this study, a flexible polydimethylsiloxane (PDMS) film with a micro-convex structure was used for the outcoupling of organic light-emitting diodes (OLEDs) using the breath figure (BF) method. The micro-convex pattern could be easily controlled by adjusting the concentration of polystyrene and the humidity during the BF process. The optical properties of the OLEDs, including transmission, diffusion, and electroluminescence, were evaluated with and without the micro-convex structure, and it was found that the shape and density of the micro-convex structure influenced the outcoupling efficiency.
Review
Chemistry, Multidisciplinary
Lei Lei, Qi Dong, Kenan Gundogdu, Franky So
Summary: Metal halide perovskites are gaining attention in optoelectronic applications due to their properties such as large absorption coefficient, low defect density, and high charge carrier mobility. While progress has been made in perovskite-based lasers, the development is still in its early stages and electrically pumped lasers have not been realized yet. Understanding the fundamental photophysical characteristics of perovskite gain materials is crucial to accelerating their development in laser applications.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Xiangyu Fu, Yash Mehta, Yi-An Chen, Lei Lei, Liping Zhu, Nilesh Barange, Qi Dong, Shichen Yin, Juliana Mendes, Siliang He, Renuka Gogusetti, Chih-Hao Chang, Franky So
Summary: The study demonstrates highly directional and polarized light emission from LEDs by selectively diffracting the TE waveguide mode, showing potential for more efficient photonic applications.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Michael Worku, Azza Ben-Akacha, Samanvitha Sridhar, Jordan R. Frick, Shichen Yin, Qingquan He, Alex J. Robb, Maya Chaaban, He Liu, J. S. Raaj Vellore Winfred, Kenneth Hanson, Franky So, Daniel Dougherty, Biwu Ma
Summary: This study reports the band edge control of perovskite emitting layers for blue PeLEDs using organic spacer cations with different dipole moments to enhance charge balance and device performance. Blue PeLEDs based on MePEA quasi-2D perovskites show twofold increase of the EQE compared to the control PEA based devices, demonstrating the effectiveness of dipole moment modification in improving performance.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Physics, Applied
Xiangyu Fu, Shichen Yin, Yi-An Chen, Liping Zhu, Qi Dong, Chih-Hao Chang, Franky So
Summary: Since the invention of organic light emitting diodes (OLEDs), research has been focused on improving efficiency and lifespan, particularly in the development of high-brightness tandem OLED structures. While high-brightness tandem OLEDs have been successfully used in displays and lighting, a major challenge lies in the low light extraction efficiency due to trapped light as waveguide modes. This perspective reviews recent works on light extraction, analyzes various extraction structures, and identifies key factors determining extraction efficiencies in tandem OLEDs.
APPLIED PHYSICS LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Stephen Amoah, Xiangyu Fu, Shichen Yin, Qi Dong, Chen Dong, Franky So
Summary: In this study, a top-emitting organic light-emitting diode (OLED) structure with a dielectric spacer and a patterned back mirror is demonstrated to enhance the light outcoupling efficiency. The optimized device shows a significant improvement in external quantum efficiency by efficiently extracting the trapped waveguide modes.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Editorial Material
Chemistry, Physical
Chenchen Yang, Harry A. Atwater, Marc A. Baldo, Derya Baran, Christopher J. Barile, Miles C. Barr, Matthew Bates, Moungi G. Bawendi, Matthew R. Bergren, Babak Borhan, Christoph J. Brabec, Sergio Brovelli, Vladimi Bulovic, Paola Ceroni, Michael G. Debije, Jose-Maria Delgado-Sanchez, Wen-Ji Dong, Phillip M. Duxbury, Rachel C. Evans, Stephen R. Forrest, Daniel R. Gamelin, Noel C. Giebink, Xiao Gong, Gianmarco Griffini, Fei Guo, Christopher K. Herrera, Anita W. Y. Ho-Baillie, Russell J. Holmes, Sung-Kyu Hong, Thomas Kirchartz, Benjamin G. Levine, Hongbo Li, Yilin Li, Dianyi Liu, Maria A. Loi, Christine K. Luscombe, Nikolay S. Makarov, Fahad Mateen, Raffaello Mazzaro, Hunter McDaniel, Michael D. McGehee, Francesco Meinardi, Amador Menendez-Velazquez, Jie Min, David B. Mitzi, Mehdi Moemeni, Jun Hyuk Moon, Andrew Nattestad, Mohammad K. Nazeeruddin, Ana F. Nogueira, Ulrich W. Paetzold, David L. Patrick, Andrea Pucci, Barry P. Rand, Elsa Reichmanis, Bryce S. Richards, Jean Roncali, Federico Rosei, Timothy W. Schmidt, Franky So, Chang-Ching Tu, Aria Vahdani, Wilfried G. J. H. M. van Sark, Rafael Verduzco, Alberto Vomiero, Wallace W. H. Wong, Kaifeng Wu, Hin-Lap Yip, Xiaowei Zhang, Haiguang Zhao, Richard R. Lunt
Summary: The lack of consensus on reporting standards in LSC-PV research hinders fair performance comparison among reports. Standardized characterization protocols are necessary for emerging PV devices to harmonize with other PV devices. The commentary highlights common limitations in LSC literature and suggests best practices for moving forward to achieve meaningful advances in LSC-PV research.
Article
Optics
Melike Biliroglu, Gamze Findik, Juliana Mendes, Dovletgeldi Seyitliyev, Lei Lei, Qi Dong, Yash Mehta, Vasily V. Temnov, Franky So, Kenan Gundogdu
Summary: Researchers have observed room-temperature superfluorescence in hybrid perovskite thin films, indicating a strong immunity to electronic dephasing in these materials. The formation of large polarons is believed to provide quantum isolation to electronic excitation and protect it from dephasing even at room temperature.
Article
Chemistry, Physical
Shichen Yin, Carr Hoi Yi Ho, Shuo Ding, Xiangyu Fu, Liping Zhu, Julian Gullett, Chen Dong, Franky So
Summary: A new strategy for efficient phase-transfer ligand exchange in large-sized quantum dots is reported. This strategy allows for the epitaxial growth of perovskite intermediate on the densely packed organic ligands and charge-neutral facets, resulting in improved film quality and enhanced photodiode performance.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Physical
Austin L. Jones, Carr Hoi Yi Ho, Sebastian A. Schneider, Junxiang Zhang, Yusen Pei, Jiayu Wang, Xiaowei Zhan, Seth R. Marder, Michael F. Toney, Franky So, G. N. Manjunatha Reddy, John R. Reynolds
Summary: This study investigates the modulation of organic solar cell efficiencies by adjusting the ionization energy level offset of polymer donors. The results show that different adjustments have different effects on the performance of solar cells. In addition, the structures of the polymers and their blends were characterized using various methods, and their roles in the performance of the cells were analyzed.
CHEMISTRY OF MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Carr Hoi Yi Ho, Yusen Pei, Yunpeng Qin, Chujun Zhang, Zhengxing Peng, Indunil Angunawela, Austin L. Jones, Hang Yin, Hamna F. Iqbal, John R. Reynolds, Kenan Gundogdu, Harald Ade, Shu Kong So, Franky So
Summary: The mobility field-dependent coefficient is found to be a key parameter determining fill factor (FF) loss in thick-film organic solar cells (OSCs). PTQ10 blend film exhibits better performance and can maintain a FF of 74% at a thickness of 300 nm.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Qi Dong, Xiangyu Fu, Dovletgeldi Seyitliyev, Kasra Darabi, Juliana Mendes, Lei Lei, Yi-An Chen, Chih-Hao Chang, Aram Amassian, Kenan Gundogdu, Franky So
Summary: Perovskite distributed feedback (DFB) lasers are attracting attention due to their solution processability, band gap tunability, single-mode operation, and low threshold. This study presents a facile approach to fabricate and design the cavities of perovskite surface-emitting DFB lasers. By adding polyvinylpyrrolidone into the perovskite precursor solutions, the cavity fabrication is simplified, and the effective index of the waveguide mode can be manipulated by varying the solution concentration. The fabricated perovskite DBF lasers achieved an optimized optical resonance and low threshold.
Review
Chemistry, Multidisciplinary
Jiyoung Moon, Yash Mehta, Kenan Gundogdu, Franky So, Qing Gu
Summary: Hybrid metal-halide perovskites (MHPs) have great potential as gain media for on-chip lasers, but the stability and patterning methods of MHP lasers still need improvement. This review aims to provide strategies for improving the properties of MHPs and establishing optimal cavity patterning methods, as well as understanding the emission mechanisms in MHP materials and cavities.
ADVANCED MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Qi Dong, Liping Zhu, Shichen Yin, Lei Lei, Kenan Gundogdu, Franky So
Summary: In this study, we demonstrate a linearly polarized organic LED with high current efficiency and large polarization ratio by utilizing the intrinsic polarization nature and transverse electric waveguide mode of thin-film LEDs. The device architecture can easily be adopted for other photonic applications, and the current efficiency can be further increased.
Article
Chemistry, Physical
C. H. Y. Ho, J. Kothari, X. Fu, F. So
Summary: The tandem structure provides a practical way to achieve high-efficiency organic solar cells by overcoming several bottlenecks in single-junction OSCs. The interconnecting layer plays a critical role in determining device performance and reproducibility in tandem OSCs. Different classes of interconnecting layers are compared based on their optical, mechanical, and chemical properties in this review paper.
MATERIALS TODAY ENERGY
(2021)
Article
Chemistry, Multidisciplinary
Eshwar Ravishankar, Melodi Charles, Yuan Xiong, Reece Henry, Jennifer Swift, Jeromy Rech, John Calero, Sam Cho, Ronald E. Booth, Taesoo Kim, Alex H. Balzer, Yunpeng Qin, Carr Hoi Yi Ho, Franky So, Natalie Stingelin, Aram Amassian, Carole Saravitz, Wei You, Harald Ade, Heike Sederoff, Brendan T. O'Connor
Summary: The study investigates the impact of adding semitransparent organic solar cells (ST-OSCs) to greenhouse structures on plant growth, finding that different OSC active layers have minimal effects on red leaf lettuce growth. OSCs also provide an opportunity for further light and thermal management in the greenhouse.
CELL REPORTS PHYSICAL SCIENCE
(2021)