scholarly journals Intermediate-phase-assisted low-temperature formation of γ-CsPbI3 films for high-efficiency deep-red light-emitting devices

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Chang Yi ◽  
Chao Liu ◽  
Kaichuan Wen ◽  
Xiao-Ke Liu ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Formation Energy ◽  
High Efficiency ◽  
Intermediate Phase ◽  
Light Emitting Diode ◽  
Red Light ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Device Applications ◽  
Low Dimensional

Abstract Black phase CsPbI3 is attractive for optoelectronic devices, while usually it has a high formation energy and requires an annealing temperature of above 300 °C. The formation energy can be significantly reduced by adding HI in the precursor. However, the resulting films are not suitable for light-emitting applications due to the high trap densities and low photoluminescence quantum efficiencies, and the low temperature formation mechanism is not well understood yet. Here, we demonstrate a general approach for deposition of γ-CsPbI3 films at 100 °C with high photoluminescence quantum efficiencies by adding organic ammonium cations, and the resulting light-emitting diode exhibits an external quantum efficiency of 10.4% with suppressed efficiency roll-off. We reveal that the low-temperature crystallization process is due to the formation of low-dimensional intermediate states, and followed by interionic exchange. This work provides perspectives to tune phase transition pathway at low temperature for CsPbI3 device applications.

Driving and Application of Blue Light Organic Light Emitting Devices

2019 ◽  
Vol 11 (5) ◽  
pp. 711-717
Author(s):  
Hongbo Liu ◽  
Minghui Liu ◽  
Lin Cong ◽  
Lizhong Wang ◽  
Tao Huang ◽  
...  
Keyword(s):  
Blue Light ◽  
High Efficiency ◽  
Low Voltage ◽  
Red Light ◽  
Portable Devices ◽  
Driving Voltage ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Organic Light Emitting Devices

The DPVBi (4,4′-bis(2,2-diphenylvinyl-1,1′-biphenyl) is a blue-light organic fluorescence doped material, which can be used as a hole barrier layer or a luminescent layer for fabricating organic light-emitting devices. A blue light device with stable color stability and high efficiency was prepared by co-doping blue light dye DPVBi and red light dye DCJTB as light-emitting layer. In order to prevent the infiltration of O2 and moisture inside the device from affecting the luminescence lifetime of the device, the device was encapsulated by atomic layer deposition. Since the driving voltage of the organic light-emitting device is generally above 5 V and the power consumption is low, in order to facilitate driving with a low voltage, a boost driving circuit based on the XL6009 chip was designed. The driver of the fabricated blue-light device was tested. The results showed that circuit had low-voltage drive characteristics and could be widely used in small toys, lighting, and portable devices. Through the test to achieve the desired goal, the requirements of low voltage and low energy consumption were realized, and the life of the light-emitting device can be tested, which has certain practicability and reference value.

scholarly journals Angle-tuned, evanescently-decoupled reflector for high-efficiency red light-emitting diode

2008 ◽  
Vol 16 (9) ◽  
pp. 6026 ◽  
Author(s):  
Sun-Kyung Kim ◽  
Hyun K. Cho ◽  
Kyung K. Park ◽  
Junho Jang ◽  
Jeong S. Lee ◽  
...  
Keyword(s):  
High Efficiency ◽  
Light Emitting Diode ◽  
Red Light ◽  
Light Emitting

Highly efficient and stable tandem organic light-emitting devices based on HAT-CN/HAT-CN:TAPC/TAPC as a charge generation layer

2015 ◽  
Vol 3 (26) ◽  
pp. 6809-6814 ◽  
Author(s):  
Yanfeng Dai ◽  
Hongmei Zhang ◽  
Zhiqiang Zhang ◽  
Yipeng Liu ◽  
Jiangshan Chen ◽  
...  
Keyword(s):  
Effective Charge ◽  
High Efficiency ◽  
Light Emitting Diode ◽  
Charge Generation ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Organic Acceptor ◽  
A Charge

We demonstrated an effective charge-generation layer (CGL) composition consisting of three layers: an organic acceptor material HAT-CN, HAT-CN blended with an organic donor material TAPC and TAPC, to fabricate a high efficiency tandem organic light-emitting diode (OLED).

scholarly journals Ultrawide Color Gamut Perovskite and CdSe/ZnS Quantum-Dots-Based White Light-Emitting Diode with High Luminous Efficiency

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1314 ◽  
Author(s):  
Chih-Hao Lin ◽  
Chieh-Yu Kang ◽  
Akta Verma ◽  
Tingzhu Wu ◽  
Yung-Min Pai ◽  
...  
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
High Efficiency ◽  
Light Emitting Diode ◽  
Red Light ◽  
Color Gamut ◽  
Television System ◽  
Light Emitting ◽  
Term Operation ◽  
Liquid Type

We demonstrate excellent color quality of liquid-type white light-emitting diodes (WLEDs) using a combination of green light-emitting CsPbBr3 and red light-emitting CdSe/ZnS quantum dots (QDs). Previously, we reported red (CsPbBr1.2I1.8) and green (CsPbBr3) perovskite QDs (PQDs)-based WLEDs with high color gamut, which manifested fast anion exchange and stability issues. Herein, the replacement of red PQDs with CdSe/ZnS QDs has resolved the aforementioned problems effectively and improved both stability and efficiency. Further, the proposed liquid-type device possesses outstanding color gamut performance (132% of National Television System Committee and 99% of Rec. 2020). It also shows a high efficiency of 66 lm/W and an excellent long-term operation stability for over 1000 h.

scholarly journals Surface/Interface Engineering for Constructing Advanced Nanostructured Light-Emitting Diodes with Improved Performance: A Brief Review

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 821 ◽  
Author(s):  
Lianzhen Cao ◽  
Xia Liu ◽  
Zhen Guo ◽  
Lianqun Zhou
Keyword(s):  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Device Performance ◽  
Interface Properties ◽  
Light Emitting ◽  
Structured Materials ◽  
Light Emitting Devices ◽  
Interface Surface ◽  
Improved Performance ◽  
Low Dimensional

With the rise of nanoscience and nanotechnologies, especially the continuous deepening of research on low-dimensional materials and structures, various kinds of light-emitting devices based on nanometer-structured materials are gradually becoming the natural candidates for the next generation of advanced optoelectronic devices with improved performance through engineering their interface/surface properties. As dimensions of light-emitting devices are scaled down to the nanoscale, the plentitude of their surface/interface properties is one of the key factors for their dominating device performance. In this paper, firstly, the generation, classification, and influence of surface/interface states on nanometer optical devices will be given theoretically. Secondly, the relationship between the surface/interface properties and light-emitting diode device performance will be investigated, and the related physical mechanisms will be revealed by introducing classic examples. Especially, how to improve the performance of light-emitting diodes by using factors such as the surface/interface purification, quantum dots (QDs)-emitting layer, surface ligands, optimization of device architecture, and so on will be summarized. Finally, we explore the main influencing actors of research breakthroughs related to the surface/interface properties on the current and future applications for nanostructured light-emitting devices.

scholarly journals Low temperature solution process-based defect-induced orange-red light emitting diode

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Pranab Biswas ◽  
Sung-Doo Baek ◽  
Sang Hoon Lee ◽  
Ji-Hyeon Park ◽  
Su Jeong Lee ◽  
...  
Keyword(s):  
Low Temperature ◽  
Light Emitting Diode ◽  
Red Light ◽  
Solution Process ◽  
Light Emitting ◽  
Temperature Solution

scholarly journals Red Light-Emitting Diodes with All-Inorganic CsPbI3/TOPO Composite Nanowires Color Conversion Films

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Lung-Chien Chen ◽  
Yi-Tsung Chang ◽  
Ching-Ho Tien ◽  
Yu-Chun Yeh ◽  
Zong-Liang Tseng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Light Emitting Diode ◽  
Red Light ◽  
Trioctylphosphine Oxide ◽  
Optical And Electrical Properties ◽  
Colloidal Solutions ◽  
High Quality ◽  
Light Emitting ◽  
Hot Injection ◽  
Color Conversion

AbstractThis work presents a method for obtaining a color-converted red light source through a combination of a blue GaN light-emitting diode and a red fluorescent color conversion film of a perovskite CsPbI3/TOPO composite. High-quality CsPbI3 quantum dots (QDs) were prepared using the hot-injection method. The colloidal QD solutions were mixed with different ratios of trioctylphosphine oxide (TOPO) to form nanowires. The color conversion films prepared by the mixed ultraviolet resin and colloidal solutions were coated on blue LEDs. The optical and electrical properties of the devices were measured and analyzed at an injection current of 50 mA; it was observed that the strongest red light intensity was 93.1 cd/m2 and the external quantum efficiency was 5.7% at a wavelength of approximately 708 nm when CsPbI3/TOPO was 1:0.35.

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