• Journal of Information Display
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• 제5권4호
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• pp.7-11
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• 2004

Effects of base vacuum level on the electrical and optical characteristics of the plasma display panel (PDP) were investigated. The relationship between efficiency and base vacuum level before filling discharge gas was analyzed. For the base vacuum level of $1{\times}10^{-4}$ torr, firing voltage of a 2-inch diagonal PDP panel was 232 V at the discharge gas pressure of 400 torr and luminous efficiency was 1.5 lm/W at 180V sustaining pulse. On the other hand for $1{\times}10^{-6}$torr, the firing voltage was reduced to 215 V and luminous efficiency was improved considerably to 2.5 lm/W. We successfully demonstrated the smooth operation of tip-less PDP fabricated using vacuum in-line sealing method.

• Transactions on Electrical and Electronic Materials
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• 제17권1호
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• pp.37-40
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• 2016

Performance enhancement of organic light-emitting diodes (OLEDs) is investigated in a device structure of ITO/TPD/Alq₃/LiF/Al and ITO/TPD/Alq₃/BCP/LiF/Al. Here, bathocuproine (BCP) is used as an electron-transport layer. Current density-voltage-luminance characteristics of the OLEDs show that the performance of the device is better with BCP layer than without BCP layer. The current density, luminance, luminous efficiency, and external-quantum efficiency are improved by approximately 22%, 50%, 2%, and 18%, respectively. Since the BCP layer lowers the electron energy barrier, electron transport is facilitated and the movement of hole is blocked as the applied voltage increases. This results in an increased recombination rate of holes and electrons.

• Journal of Information Display
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• 제4권4호
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• pp.13-18
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• 2003

One of the most important issues in AC PDP is the improvement of luminous efficiency. One possible method for achieving this aim is by increasing Xe partial pressure in discharge gas mixture. The increase of Xe ratio, however, causes the driving voltage to rise, even if brightness is increased. In this study, a new electrode shape is proposed. A test panel fabricated by using a new electrode shows that efficacy has improved by 25 % and sustain voltage has decreased by 20 % compared with the conventional structure.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.832-835
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• 2003

By using vacuum in-line driving and photoluminescence measuring method, we have observed the electrical and optical characteristics of the vacuum in-line sealing technology and analyzed the effect of the base vacuum level before filling the plasma gas. In the case of base vacuum level of $1{\times}10^{-3}$torr, the firing voltage of a 2-inch diagonal PDP panel was ranged from 310 to 345V depending on the plasma gas pressure of 200 to 300torr and luminous efficiency was ranged from 0.0227 to 0.0367 lm/W depending on the input voltage level of 330 to 225V. While, in the case of $1{\times}10^{-6}$, the characteristics were significantly improved. As a results, the firing voltage was ranged from 295 to 318V and luminous efficiency was from 0.0278 to 0.0451 lm/W.

• 전기학회논문지
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• 제60권1호
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• pp.119-123
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• 2011

We have investigated the luminous efficiency of various cell resolution and structure from 50" FHD to 50" QFHD Plasma Display. The suggested test panels have two different cell array types which are the delta and matrix cell array type. The results showed that, in the case of the suggested QFHDs, the firing and sustain voltage were increased and voltage margin was decreased. These results are caused by the reduced wall voltage and increased charged particle loss, at the side wall. The luminance of the suggested QFHDs was lower from 20% to 40% than that of the suggested FHDs and the power consumption was higher from 42% to 83% than that of the suggested FHDs. In conclusion, the maximum luminous efficiency of the suggested QFHD(D110) has reached about 38%, compared with suggested FHDs($\fallingdotseq$ 2.7 lm/W).

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.115-116
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• 2000

Influence of sustain pulse-width on electro-luminous efficiency is experimentally investigated for surface discharge of AC-PDP. It is found that the firing voltage is decreased as the pulse-width is increased from $2\;{\mu}s$ to $8\;{\mu}s$ with sweeping frequency range of 10 kHz to 50 kHz. It has been found that the optimal sustain pulse-width is in the range of $3{\sim}4\;{\mu}s$ under driving frequency range of 30 kHz and 50 kHz, based on observations of memory coefficient, wall charge, and wall voltage as well as luminous efficiency.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1658-1661
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• 2002

Up to now, one of the most serious problems in AC PDP is low luminous efficiency. One possible candidate for solving such problem is using high density Xe. But an increase of the Xe percentage cause rising of the driving voltage and so even if brightness is being increased, luminous efficiency is decreased. In this study, to solve this problem, we proposed new electrode structure. A test panel fabricated using new electrode shows an improvement of efficiency by 25% and a lowering of sustain voltage by 20% compared with the conventioned structure.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.694-697
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• 2007

We demonstrate the use of screen printing in the fabrication of highly efficient phosphorescent polymer organic-light-emitting devices (OLEDs) based on a green-emitting $Ir(ppy)_3$ and a host polymer PVK. We incorporate PBD in the polymer host as an electron-transporting dopant and ${\alpha}-NPD$ as a hole transporting dopant. The best screen printed single-layer device exhibits very high peak luminous efficiency of 63 cd/A at a relatively high operating voltage of 17.1 V at the luminance of $650\;cd/m^2$. We observed the highest luminance of $21,000\;Cd/m^2$ at 35V. Due to the high operating voltage, despite of the high peak luminous efficiency the peak power efficiency was found to be 12.2 lm/W at the luminance of $470\;cd/m^2$ (15.9 V).

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.809-812
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• 2008

Structural parameter variation effects (changing the coplanar gap under different discharge dimensions) and use of complex gas mixtures (He, Ne, Ar and Xe) in mercury-free fluorescent lamps are studied in this paper. Pure Neon gas is the best buffer gas for obtaining high luminous efficiency in mercury-free fluorescent lamps. It is shown that with a shorter coplanar gap (30mm), a high luminous efficiency can be obtained at low operating voltage, as well as high luminance uniformity and stable discharge with a Ne-Xe 20% gas mixture.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.101-104
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• 2003

The real test panel with the $200{\mu}m$ discharge gap in a coplanar AC plasma display panel was investigated. The auxiliary electrode was placed between two sustain electrodes and used for providing wall charges and prime particle during sustain period. The luminous efficiency had the maximum value when the voltage of the auxiliary pulses was 20 ${\sim}$ 100[V]. The luminous efficiency of coplanar long-gap discharge with auxiliary electrode was 2.6 times as much as that of the conventional structure.