Efficient Organe Organic Light-Emitting Devices Using N-arylbenzinmidzoles as Blocking Layer

2013 ◽  
Vol 734-737 ◽  
pp. 2273-2277
Author(s):  
Hui Shan Yang ◽  
Li Shuang Wu
Keyword(s):  
Blue Light ◽  
Applied Voltage ◽  
Light Emission ◽  
Blocking Layer ◽  
Peak Efficiency ◽  
Yellow Light ◽  
Maximum Brightness ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light

A orange organic light-emitting device has been fabricated with a structure of ITO/m-MTDATA (45 nm)/NPB (8 nm)/ DPVBi:DCJTB 0.5 % (15 nm)/TPBi (x nm)/Alq3[(60-x) n /LiF (1 nm)/Al£¬where x=0, 4, 7 and 10, respectively. N-arylbenzinmidzoles (TPBi) was used as the excton-blocking layer resulting mixture of lights from DPVBi molecules (blue-light) and DCJTB (yellow-light) molecules, thereby producing orange light emission. The performance of device can be readily adjusted by only varying the thickness of the TPBi layer. The Commission Internationale de 1'Eclairage (CIE) coordinates of the device are largely insensitive to diffrent of the driving voltages. When the thickness of TPBi is 7 nm, the device exhibits peak efficiency of 6.16 cd/A at the applied voltage of 8 V, and the maximum brightness is 43310 cd/m2at 15 V, respectively.

A Novel Efficient Blue Organic Light Emitting Structure

2005 ◽  
Vol 475-479 ◽  
pp. 3677-3680 ◽  
Author(s):  
Wen Long Jiang ◽  
Yu Duan ◽  
Yi Zhao ◽  
Jingying Hou ◽  
Shi Yong Liu
Keyword(s):  
Light Emission ◽  
Copper Phthalocyanine ◽  
Luminous Efficiency ◽  
Blocking Layer ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Carrier Recombination ◽  
Organic Light ◽  
Hole Blocking Layer ◽  
Organic Light Emitting Devices

In this paper, we describe the performance of an organic light emitting devices〔OLEDs〕 with ITO /4,4’,4“-tris{N,- （ 3-methylphenyl ） -N-phenylamino}triphenylamine (m-MTDATA) /N,N-diphenyl-N,N-bis1-naphthyl-1,1-biphenyl-4,4-diamine (NPB) /copper phthalocyanine (CuPc) / NPB / Bathocuproine(BCP) / tris-8-hydroxyquinoline Aluminum (Alq3) / LiF/ AL structure, the CuPc inserted between the two layers of NPB as a hole-consuming layer (HCL), and the BCP as a hole-blocking layer (HBL) . The EL spectrum peak is at 430 nm, indicating that the carrier recombination is confined in the NPB layer, in additional light emission originates from NPB. Compared with the luminous efficiency of the conventional diode without CuPc layer, that of the diode with HCL has been sharply increased up to 2.62 cd /A. It suggested that the CuPc and BCP exactly function as hole-consuming and hole-blocking layers, respectively, which enhance the efficiency of carrier，s recombination and confine the excitation in the EL layer.

Cavity Design and Optimization of Hybrid Quantum Dot Organic Light Emitting Devices for Blue Light Emission

2020 ◽  
Vol 15 (11) ◽  
pp. 1364-1373
Author(s):  
Iman E. Shaaban ◽  
Ahmed S. Samra ◽  
Bedir Yousif ◽  
N. A. Alghamdi ◽  
Shamia El-Sherbiny ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Blue Light ◽  
Light Emission ◽  
Cdse Qds ◽  
Blue Light Emission ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Organic Light Emitting Devices

The present search handles the blue light emission investigation of hybrid quantum dots organic light-emitting devices. The emissions at 445 nm and 460 nm have been examined for microcavity hybrid quantum dot organic light-emitting devices (QD-OLED) upon quantum dots of CdS and CdSe. External light emissions have been evaluated through a numerical model based on the transfer matrix for electromagnetic plane waves. The devices' optical properties are investigated based on internal reflectance and cavity length by considering the architecture consisting of multilayers thin-film structures. The overall performance of the light-emitting devices with emission at 445 nm showed an improvement of the enhancement factor and narrowing outcoupling emission relative to the devices with emission at 460 nm. Besides, the light-emitting devices based on CdS QDs revealed better performance relative to the devices based on CdSe QDs.

Blue and White Organic Light-Emitting Devices Using 2,5-Diphenyl -1, 4-Distyrylbenzene with Two Trans-Double Bonds as a Blue Emitting Layer

2005 ◽  
Vol 475-479 ◽  
pp. 1805-1808
Author(s):  
Gang Cheng ◽  
Zengqi Xie ◽  
Ying Fang Zhang ◽  
Yuguang Ma ◽  
Shi Yong Liu
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Maximum Efficiency ◽  
Double Bonds ◽  
Yellow Light ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Hole Transporting ◽  
Organic Light Emitting Devices

A novel derivative of oligo(phenylenvinylene) (OPV), 2,5-diphenyl -1, 4-distyrylbenzene with two trans-double bonds (trans-DPDSB), is used as a blue emitting material in blue and white organic light-emitting devices (OLEDs). Blue devices with a configuration of indium-tin oxide (ITO)/N,N´-diphenyl-N,N´-bis(1-naphthyl)-(1,1´-biphenyl)-4,4´-diamine (NPB)/ trans-DPDSB / tris (8-hydroxyquinoline) aluminum (Alq3)/LiF/Al are constructed, where NPB, Alq3 and trans-DPDSB are used as hole-transporting, electron-transporting and light-emitting layers, respectively. The color of emission is changed from blue-green to pure blue when the trans-DPDSB layer is thicker. By inserting an ultrathin 5,6,11,12-tetraphenylnaphthacene (rubrene) yellow light-emitting layer between the Alq3 and trans-DPDSB layers, white OLEDs are obtained. The maximum efficiency and luminance of the blue and white devices are 1.2, 3.0 cd/A, and 1400, 7000 cd/m2, respectively.

Yellow Organic Light-Emitting Devices Based on Alq Doped DPIHQZn

2013 ◽  
Vol 785-786 ◽  
pp. 563-566
Author(s):  
Yong Hui Gao ◽  
Zhong Qi You ◽  
Wen Long Jiang
Keyword(s):  
Applied Voltage ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Maximum Luminance ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Hole Transporting ◽  
Organic Light Emitting Devices

The Electroluminescence (EL) characteristics of a novel yellow emitting material (DPIHQZn) were investigated in this paper. The results demonstrated the DPIHQZn with strong emitting and hole-transporting ability. Based on the performance,a series of doping yellow organic light-emitting diodes were fabricated.The yellow devices were fabricated as follows: ITO/ 2T-NATA(40 nm)/NPB(10 nm)/Alq:x%DPIHQZn (35 nm)/Alq (35 nm)/LiF(5 nm)/ Al,x=1,2,3,5;the maximum luminance was 3180 cd/m2at an applied voltage of 15V,while the Commission International de LEclairage coordinates was (0.40,0.48).

Improved Yellow Light Emission in the Achievement of Dichromatic White Light Emitting Diodes

2013 ◽  
Vol 1538 ◽  
pp. 371-375
Author(s):  
Zhao Si ◽  
Tongbo Wei ◽  
Jun Ma ◽  
Ning Zhang ◽  
Zhe Liu ◽  
...  
Keyword(s):  
Blue Light ◽  
White Light ◽  
Light Emitting Diodes ◽  
Light Emission ◽  
Dual Wavelength ◽  
Emission Wavelength ◽  
White Led ◽  
Yellow Light ◽  
Light Emitting ◽  
White Light Emitting Diodes

ABSTRACTA study about the achievement of dichromatic white light-emitting diodes (LEDs) was performed. A series of dual wavelength LEDs with different last quantum-well (LQW) structure were fabricated. The bottom seven blue light QWs (close to n-GaN layer) of the four samples were the same. The LQW of sample A was 3 nm, and that of sample B, C and D were 6 nm, a special high In content ultra-thin layer was inserted in the middle of the LQW of sample C and on top of that of sample D. XRD results showed In concentration fluctuation and good interface quality of the four samples. PL measurements showed dual wavelength emitting, the blue light peak position of the four samples were almost the same, sample A with a narrower LQW showed an emission wavelength much shorter than that of sample B, C, D. EL measurement was done at an injection current of 100 mA. Sample A only showed LQW emission due to holes distribution. Because of wider LQW, the emission wavelength of sample B, C and D was longer and peak intensity was weaker. Sample D with insert layer on top of LQW showed strongest yellow light emission with a blue peak. As the injection current increased, sample A showed highest output light power due to narrower LQW. Of the other three samples with wider LQW, sample D showed highest output power. Effective yellow light emission has always been an obstacle to the achievement of dichromatic white LED. Sample D with insert layer close to p-GaN can confine the hole distribution more effectively hence the recombination of holes and electrons was enhanced, the yellow light emission was improved and dichromatic white LED was achieved.

Tuning optical properties of CsPbBr3 by mixing Nd3+trivalent lanthanide halide cations for blue light emitting devices.

2022 ◽  
Author(s):  
Muhammad Amin Padhiar ◽  
Minqiang Wang ◽  
Yongqiang Ji ◽  
Zhi Yang ◽  
Arshad Saleem Bhatti
Keyword(s):  
Optical Properties ◽  
Blue Light ◽  
Light Emission ◽  
Low Cost ◽  
Thermal Quenching ◽  
Visible Spectrum ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Lanthanide Halide ◽  
Trivalent Lanthanide

Abstract In recent years, significant progress has been made in the red and green perovskite quantum dots (PQDs) based light-emitting devices. However, a scarcity of blue-emitting devices that are extremely efficient precludes their research and development for optoelectronic applications. Taking advantage of tunable bandgaps of PQDs over the entire visible spectrum, herein we tune optical properties of CSPbBr3 by mixing Nd3+ trivalent lanthanide halide cations for blue light-emitting devices. The CsPbBr3 PQDs doped with Nd3+ trivalent lanthanide halide cations emitted strong photoemission from green into the blue region. By adjusting their doping concentration, a tunable wavelength from (515 nm) to (450 nm) was achieved with FWHM from (37.83 nm) to (16.6 nm). We simultaneously observed PL linewidth broadening thermal quenching of PL and the blue shift of the optical bandgap from temperature-dependent PL studies. The Nd3+ cations into CsPbBr3 PQDs more efficiently reduced non-radiative recombination. As a result of the efficient removal of defects from PQDs, the photoluminescence quantum yield (PLQY) has been significantly increased to 91% in the blue-emitting region. Significantly, Nd3+ PQDs exhibit excellent long-term stability against the external environment, including water, temperature, and ultraviolet light irradiation. Moreover, we successfully transformed Nd3+ doped PQDs into highly fluorescent nanocomposites. Incorporating these findings, we fabricate and test a stable blue light-emitting LED with EL emission at (462 nm), (475 nm), and successfully produce white light emission from Nd3+ doped nanocomposites with a CIE at (0.32, 0.34), respectively. The findings imply that low-cost Nd3+ doped perovskites may be attractive as light converters in LCDs with a broad color gamut.

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