• Title/Summary/Keyword: Blue Emitter

Search Result 39, Processing Time 0.027 seconds

Enforced Effects of Bulky Side Groups and Side Group Substitution Position on OLED High Performance: How to Control Side Groups for Highly Efficient Blue Emitters?

  • Park, Young-Il;Kim, Soo-Kang;Jaung, Jae-Yun;Park, Jong-Wook
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2009.10a
    • /
    • pp.493-496
    • /
    • 2009
  • We report the EL property of blue and blue-violet emitting materials with anthracene moiety as well as a new core structure containing indenopyrazine. Non-doped device using one of indenopyrazine core derivatives was found to exhibit excellent blue-violet color purity of (0.173, 0.063), and narrow emission band of 42nm FWHM. One of anthracene core derivatives with bulky side group also exhibits excellent color coordinates (0.156, 0.088) and an external quantum efficiency of 7.18%.

  • PDF

Highly Efficient Multi-Functional Material for Organic Light-Emitting Diodes; Hole Transporting Material, Blue and White Light Emitter

  • Kim, Myoung-Ki;Kwon, Jong-Chul;Hong, Jung-Pyo;Lee, Seong-Hoon;Hong, Jong-In
    • Bulletin of the Korean Chemical Society
    • /
    • v.32 no.spc8
    • /
    • pp.2899-2905
    • /
    • 2011
  • We have demonstrated that TPyPA can be used as an efficient multi-functional material for OLEDs; hole transporting material (HTL), blue and white-light emitter. The device based on TPyPA as the HTL exhibited an external quantum efficiency of 1.7% and a luminance efficiency of 4.2 cd/A; these values are 40% higher than the external quantum efficiency and luminance efficiency of the NPD-based reference device. The device based on TPyPA as a blue-light emitter exhibited an external quantum efficiency of 4.2% and a luminance efficiency of 5.3 $cdA^{-1}$ with CIE coordinates at (0.16, 0.14), the device based on TPyPA as a white-light emitter exhibited an external quantum efficiency of 3.2% and a luminance efficiency of 7.7 $cdA^{-1}$ with CIE coordinates at (0.33, 0.39). Also, TPyPA-based organic solar cell (OSC) exhibited a maximum power conversion efficiency of 0.35%. TPyPA-based organic thin-film transistors (OTFTs) exhibited highly efficient field-effect mobility (${\mu}_{FET}$) of $1.7{\times}10^{-4}cm^2V^{-1}s^{-1}$, a threshold voltage ($V_{th}$) of -15.9 V, and an on/off current ratio of $8.6{\times}10^3$.

Improved EL efficiency and operational lifetime of top-emitting white OLED with a co-doping technology

  • Lee, Meng-Ting;Tseng, Mei-Rurng
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2007.08b
    • /
    • pp.1411-1414
    • /
    • 2007
  • We have developed a top-emitting white organic electroluminescent device (TWOLED) incorporating a low-reflectivity molybdenum (Mo) anode and doped transport layers as well as a dual-layer architecture of doped blue and yellow emitters with the same blue host. The EL efficiency and operational lifetime of TWOLED can be enhanced by a factor of 1.2 and 3.4 than that of standard TWOLED, respectively, with a co-doping technology in yellow emitter by doping another blue dopant. The enhancement in device performances can be attributed to improve the energy transfer efficiency from blue host to yellow dopant through a blue dopant as medium in yellow emitter.

  • PDF

Design analysis of high efficiency crystalline silicon solar cell using the selective emitter (선택적 에미터를 적용한 고효율 결정질 실리콘 태양전지 구조 설계)

  • Lim, Jong-Keun;Lee, Won-Jae;Moon, In-Sik;Oh, Hoon;Cho, Eun-Chel
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2009.11a
    • /
    • pp.355-358
    • /
    • 2009
  • This paper presents the technology of selective emitter for high efficiency crystalline silicon solar cell. The effect of selective emitter is analyzed by using the simulation program for solar cell, PC1D. The selective emitter shows better spectral response in short wavelength regions compared to homogeneous emitter. Therefore, the efficiency of solar cell with selective emitter can be improved by changing the sheet resistance from 60 $\Omega/\square$ to 120 $\Omega/\square$. In addition, the power loss of solar cell can be minimized by optimizing width and gap of the finger electrodes on the selective emitter.

  • PDF

Color stable and efficient white organic light emitting diodes with phosphorescent emitters

  • Lee, Hyun-Koo;Lee, Chang-Hee
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2009.10a
    • /
    • pp.415-417
    • /
    • 2009
  • Color stable and efficient two wavelength white organic light emitting diodes (OLEDs) were fabricated using a iridium(III)[bis(4,6-difluorophenyl)-pyridinato-N,$C^2$'] picolinate (FIrpic) as a blue phosphorescent emitter and a bis(1-phenylisoquinolinato-$C^2$,N)iridium (acetylacetonate) ((piq)$_2$Ir(acac)) as a red phosphorescent emitter. The emitting layers consist of two blue emitting layers and one red emitting layer which is between the two blue layers. The device reaches the peak efficiencies of 7.84 % and 10.3 cd/A at 0.6 mA/$cm^2$. Furthermore, there was little change of EL spectra according to current density change in the device.

  • PDF

Contact Resistance Analysis of High-Sheet-Resistance-Emitter Silicon Solar Cells (고면저항 에미터 결정질 실리콘 태양전지의 전면전극 접촉저항 분석)

  • Ahn, Jun-Yong;Cheong, Ju-Hwa;Do, Young-Gu;Kim, Min-Seo;Jeong, Ji-Weon
    • New & Renewable Energy
    • /
    • v.4 no.2
    • /
    • pp.74-80
    • /
    • 2008
  • To improve the blue responses of screen-printed single crystalline silicon solar cells, we investigated an emitter etch-back technique to obtain high emitter sheet resistances, where the defective dead layer on the emitter surface was etched and became thinner as the etch-back time increased, resulting in the monotonous increase of short circuit current and open circuit voltage. We found that an optimal etch-back time should be determined to achieve the maximal performance enhancement because of fill factor decrease due to a series resistance increment mainly affected by contact and lateral resistance in this case. To elucidate the reason for the fill factor decrease, we studied the resistance analysis by potential mapping to determine the contact and the lateral series resistance. As a result, we found that the fill factor decrease was attributed to the relatively fast increase of contact resistance due to the dead layer thinning down with the lowest contact resistivity when the emitter was contacted with screen-printed silver electrode.

  • PDF

CONTACT RESISTANCE ANALYSIS OF HIGH-SHEET-RESISTANCE-EMITTER SILICON SOLAR CELLS (고면저항 에미터 결정질 실리콘 태양전지의 전면전극 접촉저항 분석)

  • Ahn, Jun-Yong;Cheong, Ju-Hwa;Do, Young-Gu;Kim, Min-Seo;Jeong, Ji-Weon
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2008.05a
    • /
    • pp.390-393
    • /
    • 2008
  • To improve the blue responses of screen-printed single crystalline silicon solar cells, we investigated an emitter etch-back technique to obtain high emitter sheet resistances, where the defective dead layer on the emitter surface was etched and became thinner as the etch-back time increased, resulting in the monotonous increase of short circuit current and open circuit voltage. We found that an optimal etch-back time should be determined to achieve the maximal performance enhancement because of fill factor decrease due to a series resistance increment mainly affected by contact and lateral resistance in this case. To elucidate the reason for the fill factor decrease, we studied the resistance analysis by potential mapping to determine the contact and the lateral series resistance. As a result, we found that the fill factor decrease was attributed to the relatively fast increase of contact resistance due to the dead layer thinning down with the lowest contact resistivity when the emitter was contacted with screen-printed silver electrode.

  • PDF

Synthesis and EL Properties of Blue Light-emitting Poly(arylenevinylene)s

  • Hwang, Do-Hoon
    • Journal of Information Display
    • /
    • v.3 no.1
    • /
    • pp.1-5
    • /
    • 2002
  • A series of fully conjugated polymers containing new arylenevinylene units were synthesized and their light-emitting properties were investigated. A bisphosphonate containing tetraphenyl group was made to react with three different dialdehyde monomers to produce fully conjugated alternating copolymers. The photoluminescence (PL) and the electroluminescence (EL) peak wavelengths of the polymers were varied from 500 nm to 460 nm depending on the polymer structure. Single layer EL devices using the polymers as an emissive layer have been fabricated. The single layer EL devices became visible between 12-22 V and emitted blue light.