Review
Chemistry, Multidisciplinary
Lingmei Kong, Xiaoyu Zhang, Chengxi Zhang, Lin Wang, Sheng Wang, Fan Cao, Dewei Zhao, Andrey L. Rogach, Xuyong Yang
Summary: Metal halide perovskites exhibit excellent electronic and optical properties, making them attractive for low-cost, large-area processing in optoelectronics. However, achieving stability and spectral stability remains a challenge. This review explores the origins of instability in perovskite materials and strategies for improving stability, as well as methods to enhance operational stability in perovskite LEDs.
ADVANCED MATERIALS
(2022)
Article
Optics
Longxue Cao, Yang Shen, Bing Lei, Wei Zhou, Shuhong Li, Yunlong Liu, Yu Lu, Kai Zhang, Hao Ren, Yan-Qing Li, Jian-Xin Tang, Wenjun Wang
Summary: A method of controlling the crystallization of reduced-dimensional mixed-halide blue perovskite films by adjusting the precursor concentration is proposed, improving the efficiency and stability of sky-blue and pure-blue perovskite light-emitting diodes (PeLEDs).
LASER & PHOTONICS REVIEWS
(2023)
Review
Physics, Multidisciplinary
Ziming Chen, Zhenchao Li, Thomas R. Hopper, Artem A. Bakulin, Hin-Lap Yip
Summary: The article provides a comprehensive review of the newly developed lighting technology based on metal halide perovskites, covering materials, photophysics, and device engineering. It focuses on the compositional engineering of perovskite structures, physics underlying photo- and electroluminescence, and strategies for boosting device performance in perovskite light-emitting diodes. Key concepts include balancing electron/hole injection, suppression of parasitic carrier losses, improvement of photoluminescence quantum yield, and enhancement of light extraction.
REPORTS ON PROGRESS IN PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Songman Ju, Chaomin Mao, Jinping Zheng, Kaiyu Yang, Lihua Lin, Tailiang Guo, Hailong Hu, Fushan Li
Summary: This work proposes a new strategy to enhance the electroluminescent performance of perovskite quantum dots (PQDs) by creating a PQD film. By manipulating the ion distribution and trap density in the PQD film through varying pre-bias voltage and time, the device's capacitance value and luminous efficiency can be modified. The external quantum efficiency of the device increased from 2.81% to 7.95% through this strategy. This research provides a new approach for achieving perovskite quantum dot light-emitting devices with high luminous efficiency.
ACS APPLIED NANO MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Qiangqiang Wang, Shuo Ding, Siliang He, Ting Zhang, Lei Qian, Peng Xiao, Tao Chen, Chaoyu Xiang
Summary: This study demonstrates the feasibility of significant stability improvement for PeLEDs using a simple cation engineering strategy, in which long-chain phenylbutanammonium is used to effectively suppress ion migration inside the PeLEDs.
ADVANCED OPTICAL MATERIALS
(2023)
Review
Optics
Runnan Yu, Changxiao Li, Biao Zhao, Zhan'ao Tan
Summary: This work reviews the research history of green perovskite light-emitting diodes (GPeLEDs), introduces perovskites of different dimensions, and discusses the common synthesis methods of perovskites. Additionally, strategies to improve the stability and luminous efficiency of GPeLEDs are summarized, including component engineering, phase engineering, ligand engineering, additive engineering, interface engineering, and optical coupling structure strategy. Finally, the development state of GPeLEDs is summarized and future prospects are discussed.
LASER & PHOTONICS REVIEWS
(2023)
Review
Chemistry, Multidisciplinary
Wenhuai Feng, Ying Tan, Meifang Yang, Yong Jiang, Bing-Xin Lei, Lianzhou Wang, Wu-Qiang Wu
Summary: Amines, featuring the combination of amino groups and other organic moieties, have shown great potential as additives or surface ligands for improving the performances of perovskite solar cells and perovskite-based light emitting diodes. By rational tailoring of their molecular structures, amine molecules exhibit multifunctionalities and salient advantages. This review unlocks the secrets of how a small amount of amine molecules incorporated in perovskite films can bring big benefits to these optoelectronic devices and discusses feasible rules for the design of amines with ideal molecular structures.
Article
Materials Science, Multidisciplinary
Kwan Ho Ngai, Qi Wei, Zefeng Chen, Xinlu Guo, Minchao Qin, Fangyan Xie, Christopher Chang Sing Chan, Guichuan Xing, Xinhu Lu, Jian Chen, Kam Sing Wong, Jianbin Xu, Mingzhu Long
Summary: The BDA-PeLED exhibits significantly enhanced stability with a record operational half-lifetime T-50 of 189.4 hours at high current density. The main origins of instability in PeLEDs without BDA are the generation of deep traps at interfaces and the infiltration of anions under long-term electric stress.
ADVANCED OPTICAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Boning Han, Shichen Yuan, Bo Cai, Jizhong Song, Wenqiang Liu, Fengjuan Zhang, Tao Fang, Changting Wei, Haibo Zeng
Summary: A methylene-bis-acrylamide cross-linking strategy is proposed to enhance the stability of perovskite light-emitting diodes (PeLEDs) by increasing the binding energy and activation energy, thereby preventing ions from migrating inside and across crystals. This strategy not only improves the external quantum efficiency, but also extends the half-life of the devices, making them more stable during continuous operation.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Nan Li, Sofia Apergi, Christopher C. S. Chan, Yongheng Jia, Fangyan Xie, Qiong Liang, Gang Li, Kam Sing Wong, Geert Brocks, Shuxia Tao, Ni Zhao
Summary: By using diammonium halides to regulate the formation of mixed bromide-iodide perovskite films, the performance of 3D mixed-halide perovskite-based light-emitting diodes (LEDs) can be improved, resulting in devices with record luminance and half-lifetime.
ADVANCED MATERIALS
(2022)
Review
Engineering, Electrical & Electronic
Azhar Fakharuddin, Mahesh K. Gangishetty, Mojtaba Abdi-Jalebi, Sang-Hyun Chin, Abd Rashid bin Mohd Yusoff, Daniel N. Congreve, Wolfgang Tress, Felix Deschler, Maria Vasilopoulou, Henk J. Bolink
Summary: Light-emitting diodes based on halide perovskites have achieved significant progress in recent years, with external quantum efficiencies surpassing 23%. However, their practical application is still limited due to factors such as low efficiency in blue-emitting devices, inability to access emission wavelengths above 800 nm, decreased external quantum efficiency at high current density, lack of understanding of the electric field's effect on mobile ions in perovskite materials, and short device lifetimes. This review explores the development of perovskite light-emitting diodes, examining the key challenges in creating efficient and stable devices.
NATURE ELECTRONICS
(2022)
Review
Chemistry, Multidisciplinary
Dexin Yang, Baodan Zhao, Tao Yang, Runchen Lai, Dongchen Lan, Richard H. Friend, Dawei Di
Summary: Metal halide perovskites, a promising class of materials for display and lighting applications, have seen a rapid increase in device efficiencies. However, challenges remain in achieving high operational stability and efficient blue emission. Interdisciplinary research involving materials scientists, chemists, and physicists is crucial for realizing operationally stable PeLEDs.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Yongheng Jia, Hui Yu, Yang Zhou, Nan Li, Yuwei Guo, Fangyan Xie, Zhaotong Qin, Xinhui Lu, Ni Zhao
Summary: The mechanism behind EQE roll-off in high-efficiency PeLEDs was investigated, revealing that migration and segregation of excess iodide ions from nonstoichiometric precursors triggered imbalanced charge injection. A simple wash-off treatment with chloroform and an ultra-thin PMMA interlayer were introduced to effectively suppress the roll-off behavior, leading to the achievement of high-brightness PeLEDs with improved performance.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Xinyu Shen, Hua Wu, Xiaoyu Zhang, Meili Xu, Junhua Hu, Jinyang Zhu, Bin Dong, William W. Yu, Xue Bai
Summary: The all-solution process for inorganic perovskite nanocrystals (PNCs) LEDs shows great potential for new-generation illumination and displays, but the challenge lies in the injection barriers and charge injection imbalance. The introduction of CBP into the hole transport layer (HTL) efficiently modulates the charge carrier mobility and energy level, resulting in barrier-free charge injection and optimal performance for solution-processed PNC LEDs. The luminance of red LEDs reaches 2990 cd m(-2) and the external quantum efficiency achieves 8.1%, with improved turn-on voltage and roll-off due to more balanced charge injection.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Yong-Chun Ye, Yang Shen, Wei Zhou, Shi-Chi Feng, Jiang-Ying Wang, Yan-Qing Li, Jian-Xin Tang
Summary: Perovskite light-emitting diodes (PeLEDs) show promise for next-generation high-definition displays due to their excellent color purity and low power consumption. A novel strategy of interfacial molecule control is demonstrated using a bifunctional material to enhance interaction and exciton management between the perovskite and electron-transport layers. This modification layer not only passivates surface defects but also blocks interfacial exciton transfer, resulting in improved external quantum efficiencies for green, blue, and red emissions.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jianming Chen, Jun Zhang, Jinlian Hu, Ningqi Luo, Fengxin Sun, Harun Venkatesan, Ni Zhao, Yuanting Zhang
Summary: By redesigning the yarn structure of textiles, the hysteresis issue in textile sensors is effectively addressed, resulting in a pressure sensor with superior recovery index, response time, and monitoring capabilities.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Nan Li, Sofia Apergi, Christopher C. S. Chan, Yongheng Jia, Fangyan Xie, Qiong Liang, Gang Li, Kam Sing Wong, Geert Brocks, Shuxia Tao, Ni Zhao
Summary: By using diammonium halides to regulate the formation of mixed bromide-iodide perovskite films, the performance of 3D mixed-halide perovskite-based light-emitting diodes (LEDs) can be improved, resulting in devices with record luminance and half-lifetime.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Yunfang Tong, Xiaoying Bi, Shuang Xu, Hao Min, Lu Cheng, Zhiyuan Kuang, Lingzhi Yuan, Fuyi Zhou, Ying Chu, Lei Xu, Lin Zhu, Ni Zhao, Nana Wang, Wei Huang, Jianpu Wang
Summary: An in situ halide exchange method is developed to achieve efficient and bright deep-blue perovskite-based LEDs. By spin-coating an organic halide salts solution to treat blue perovskites, the halide-exchange process leads to homogeneous mixed-halide perovskites. Introduction of multifunctional organic ammonium halide salts further reduces trap density and improves the quality of deep-blue perovskites.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Xin Wu, Danpeng Gao, Xianglang Sun, Shoufeng Zhang, Qi Wang, Bo Li, Zhen Li, Minchao Qin, Xiaofen Jiang, Chunlei Zhang, Zhuo Li, Xinhui Lu, Nan Li, Shuang Xiao, Xiaoyan Zhong, Shangfeng Yang, Zhong'an Li, Zonglong Zhu
Summary: In this study, a simple design strategy of polymer hole-transporting materials (HTMs) is reported, which can modulate the wettability and promote the anchoring by introducing pyridine units into the polyarylamine backbone, resulting in efficient and stable inverted perovskite solar cells (PVSCs).
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Danpeng Gao, Bo Li, Zhen Li, Xin Wu, Shoufeng Zhang, Dan Zhao, Xiaofen Jiang, Chunlei Zhang, Yan Wang, Zhenjiang Li, Nan Li, Shuang Xiao, Wallace C. H. Choy, Alex K. -Y. Jen, Shangfeng Yang, Zonglong Zhu
Summary: A highly efficient and stable flexible perovskite solar cell (PSC) is reported by modifying the interface between perovskite and hole transport layer using pentylammonium acetate (PenAAc) molecule. The PenAAc-modified PSC achieves a record power conversion efficiency (PCE) of 23.68% and shows excellent stability under mechanical bending.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yu Zhang, Bryan D. D. Paulsen, Emily A. A. Schafer, Qiming Zeng, Fei Yu, Li Yang, Yan Xue, Jonathan Rivnay, Ni Zhao
Summary: Bioelectronics based on organic mixed conductors have great potential in applications such as biological interfacing, drug delivery systems, and neuromorphic devices. This study quantifies the injection of ions and water in polymeric mixed conductors and analyzes the change in molecular packing. The penetration of ions and water can disrupt the microstructure of organic mixed conductors, with water uptake playing a more dominant role. The study demonstrates the potential application of a combined optical, gravimetric, and electrical platform in evaluating the structural kinetics of organic mixed conductors.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yihao Li, Yan Huang, Ni Zhao
Summary: Low-cost and wearable heart sound sensors can facilitate early detection and monitoring of cardiovascular and respiratory diseases. By using a hybrid near-field/far-field electrospinning approach, a new heart sound sensor with high sensitivity and low detection limit is demonstrated. The sensor can be integrated with apparel and capture high-quality heart sound signals to distinguish different cardiovascular diseases.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Computer Science, Information Systems
Shirong Qiu, Yuan-Ting Zhang, Sze-Kei Lau, Ni Zhao
Summary: A pattern-fusion method is proposed to improve the accuracy of cuffless blood pressure measurement by incorporating cardiovascular coupling effects in the vascular model through three calculation modules.
IEEE JOURNAL OF BIOMEDICAL AND HEALTH INFORMATICS
(2023)
Review
Health Care Sciences & Services
Lei Zhao, Cunman Liang, Yan Huang, Guodong Zhou, Yiqun Xiao, Nan Ji, Yuan-Ting Zhang, Ni Zhao
Summary: Cardiovascular diseases (CVDs) are one of the major causes of death worldwide, and monitoring blood pressure (BP) is vital for their early diagnosis and management. This review focuses on wearable and cuffless BP monitoring technologies, including flexible sensor designs and BP extraction algorithms. The sensors are classified into electrical, optical, and mechanical types, and the review briefly discusses the choices, fabrication methods, and performances of each type. The review also introduces contemporary algorithmic methods for beat-to-beat BP measurements and continuous BP waveform extraction, comparing their features and performances.
NPJ DIGITAL MEDICINE
(2023)
Article
Chemistry, Physical
Zhiwen Zhou, Qihua Li, Mojun Chen, Xuerong Zheng, Xiao Wu, Xinhui Lu, Shuxia Tao, Ni Zhao
Summary: In this study, a strategy of additive engineering was used to improve the stability and performance of field-effect transistors (FETs) based on 3D formamidinium tin iodide (FASnI(3)) films. By studying the effects of different additives, it was discovered that phenethyl-ammonium (PEA) and its fluorinated derivative (FPEA) can enhance the crystallization of FASnI(3) films and reduce structural defects. The optimized FPEA-modified FASnI(3) FETs showed record high field-effect mobility and excellent stability.
ACS ENERGY LETTERS
(2023)
Article
Chemistry, Physical
Shenghe Zhao, Hui Yu, Yongheng Jia, Yang Zhou, Zheng Zhang, Ni Zhao
Summary: Postdeposition halide exchange is a popular strategy for tuning the emission wavelength of metal halide perovskites, especially in achieving deep-blue perovskite light-emitting diodes (PeLEDs). This study investigates the halide exchange strategy for deep-blue PeLEDs and focuses on understanding the role of the organic cations of the halide salt in modifying the properties of the perovskite films and PeLED performances. The results highlight the importance of organic cation selection in the halide exchange processes for PeLEDs.
Article
Chemistry, Physical
Yongheng Jia, Ruichen Li, Yang Zhou, Shenghe Zhao, Hui Yu, Jianpu Wang, Zhenyang Lin, Haibin Su, Ni Zhao
Summary: Perovskite light-emitting diodes (PeLEDs) based on 3D mixed Br-Cl compositions exhibit good color stability and efficiency in the sky-blue range, but suffer from a significant performance decay in the deep-blue emission. This decay is mainly attributed to the poor morphology of the emissive layer. By combining theoretical and experimental approaches, it is discovered that the exchange of halide ions in lead complexes drives the precipitation of CsCl, resulting in low solubility at high Cl/Br ratios and inadequate perovskite film coverage. A metastable dissolution strategy is proposed, leading to deep-blue PeLEDs with a record high EQE of 4% and excellent spectral stability.
Article
Engineering, Electrical & Electronic
Shuyan Chen, Hui Yu, Ni Zhao, Lian-Kuan Chen
Summary: This article investigates the dynamic impedance of photovoltaic (PV) modules and its effect on PV frequency response under different illuminances. It proposes a simplified yet accurate AC model for PV detection and validates its effectiveness through experimental results. The study finds that the internal resistance and capacitance of PV modules depend on incident illuminance, affecting the frequency response. By adjusting the forward bias conditions and optimizing the equivalent trans-impedance, the data rate and bit error rate of PV modules can be significantly improved.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Ze Chen, Yue Hou, Yiqiao Wang, Zhiquan Wei, Ao Chen, Pei Li, Zhaodong Huang, Nan Li, Chunyi Zhi
Summary: Utilizing diphenyl diselenide as the anchoring agent, an atomic level chlorine fixation is achieved through chalcogen-halogen coordinating chemistry, leading to improved battery reversibility and electrochemical performance.
ADVANCED MATERIALS
(2023)
