scholarly journals Directional and Fast Photoluminescence from CsPbI3 Nanocrystals Coupled to Dielectric Circular Bragg Gratings

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 422
Author(s):  
Yan Hua ◽  
Yuming Wei ◽  
Bo Chen ◽  
Zhuojun Liu ◽  
Zhe He ◽  
...  

Lead halide perovskite nanocrystals (NCs), especially the all-inorganic perovskite NCs, have drawn substantial attention for both fundamental research and device applications in recent years due to their unique optoelectronic properties. To build high-performance nanophotonic devices based on perovskite NCs, it is highly desirable to couple the NCs to photonic nanostructures for enhancing the radiative emission rate and improving the emission directionality of the NCs. In this work, we synthesized high-quality CsPbI3 NCs and further coupled them to dielectric circular Bragg gratings (CBGs). The efficient couplings between the perovskite NCs and the CBGs resulted in a 45.9-fold enhancement of the photoluminescence (PL) intensity and 3.2-fold acceleration of the radiative emission rate. Our work serves as an important step for building high-performance nanophotonic light emitting devices by integrating perovskite NCs with photonic nanostructures.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Young Ran Park ◽  
Sangwon Eom ◽  
Hong Hee Kim ◽  
Won Kook Choi ◽  
Youngjong Kang

Abstract Halide vacancy defect is one of the major origins of non-radiative recombination in the lead halide perovskite light emitting devices (LEDs). Hence the defect passivation is highly demanded for the high-performance perovskite LEDs. Here, we demonstrated that FA doping led to the enrichment of Br in Cs1−xFAxPbBr3 QDs. Due to the defect passivation by the enriched Br, the trap density in Cs1−xFAxPbBr3 significantly decreased after FA doping, and which improved the optical properties of Cs1−xFAxPbBr3 QDs and their QD-LEDs. PLQY of Cs1–xFAxPbBr3 QDs increased from 76.8% (x = 0) to 85.1% (x = 0.04), and Lmax and CEmax of Cs1–xFAxPbBr3 QD-LEDs were improved from Lmax = 2880 cd m−2 and CEmax = 1.98 cd A−1 (x = 0) to Lmax = 5200 cd m−2 and CEmax = 3.87 cd A−1 (x = 0.04). Cs1–xFAxPbBr3 QD-LED device structure was optimized by using PVK as a HTL and ZnO modified with b-PEI as an ETL. The energy band diagram of Cs1–xFAxPbBr3 QD-LEDs deduced by UPS analyses.


2021 ◽  
Vol 2015 (1) ◽  
pp. 012153
Author(s):  
Pavel Tonkaev ◽  
Sergey Makarov

Abstract Hyperbolic metamaterials represent a class of nanophotonic architectures with the possibility of controlling density of optical states. Due to this property, hyperbolic metamaterials can be employed as meta-electrodes in optoelectronic devices. On the other hand, lead halide perovskites have several promising properties for application in light-emitting devices. Moreover, a perovskite film is easily deposited on a hyperbolic metamaterial surface. Here, we theoretically show how to accelerate radiative recombination in a perovskite film with a hyperbolic metamaterial. This effect can be applied in light-emitting devices, where radiative recombination is extremely important.


2000 ◽  
Vol 78 (3) ◽  
pp. 231-241 ◽  
Author(s):  
M D'Iorio

Molecular organic materials have had an illustrious past but the ability to deposit these as homogeneous thin films has rejuvenated the field and led to organic light-emitting diodes (OLEDs) and the development of an increasing number of high-performance polymers for nonlinear and electronic applications. Whereas the use of organic materials in micro-electronics was restricted to photoresists for patterning purposes, polymeric materials are coming of age as metallic interconnects, flexible substrates, insulators, and semiconductors in all-plastic electronics. The focus of this topical review will be on organic light-emitting devices with a discussion of the most recent developments in electronic devices.PACS Nos.: 85.60Jb, 78.60Fi, 78.55Kz, 78.66Qn, 73.61Ph, 72.80Le


2015 ◽  
Vol 6 (8) ◽  
pp. 4623-4635 ◽  
Author(s):  
Gang Cheng ◽  
Gary Kwok-Ming So ◽  
Wai-Pong To ◽  
Yong Chen ◽  
Chi-Chung Kwok ◽  
...  

High performance orange (EQE up to 15.64%) and white (EQE up to 6.88%) solution processed OLEDs fabricated solely with emitters of non-platinum group metals were reported. The white device has CIE coordinates of (0.42, 0.44) and CRI of 81.


Author(s):  
Xiaokang Li ◽  
Wenxing Liu ◽  
Kai Chen ◽  
Ruixia Wu ◽  
Guo-Jun Liu ◽  
...  

Abstract In this work, we have experimentally demonstrated the efficacy of micro-cavity effect in realizing high-performance top-emitting organic light-emitting diodes (TEOLEDs). By optimizing the thickness of top Yb/Ag electrode and cavity length, highly efficient green TEOLED with external quantum efficiency as high as 38% was achieved. A strong dependence of electroluminescent (EL) performances and spectrum on cavity length was observed, and there was also a significant angle dependence of EL spectrum. Ultimately, ultra-high current efficiency up to 161.17 cd/A (3.2 V) was obtained by the device with emission peak at 552 nm, which is 35 nm longer than the intrinsic emission peak (517 nm) of utilized green emitter. Interestingly, this device displayed narrow emission with full-width at half-maximum (FWHM) of less than 20 nm, which was obtained by increasing the Ag layer thickness.


Author(s):  
Yao Li ◽  
Kaimin Du ◽  
Manli Zhang ◽  
Xuan Gao ◽  
Yu Lu ◽  
...  

Metal halide perovskites are a new class of promising materials in optoelectronic applications. As optoelectronic properties of the lead halide perovskites are determined largely by their morphology, the morphology of...


Nanoscale ◽  
2018 ◽  
Vol 10 (43) ◽  
pp. 20131-20139 ◽  
Author(s):  
Fei Zhang ◽  
Zhi-Feng Shi ◽  
Zhuang-Zhuang Ma ◽  
Ying Li ◽  
Sen Li ◽  
...  

CsPbBr3 QDs/silica composites with substantially improved stability were applied as the color-converting layer for high-performance white LED fabrication.


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