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The Global ETD Search service is a free service for researchers
to find electronic theses and dissertations. This service is
provided by the
Networked Digital Library of Theses and Dissertations.
Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
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Showing 21 to 30 of 684 (0.02 seconds)| 21 |
The study of high efficiency white organic light emitting diodesTseng, Ching-huei 13 February 2007 (has links)
Three subjects on the organic light-emitting diodes (OLEDs) have been studied. First, We inserted a NPB¡GAlq3 mixed layer between these two NPB and Alq3 layers to decrease the holes mobility and improve the combined efficiency between the holes and electrons. After inserting the NPB¡GAlq3 layer, the current density of the device( ITO/ MTDATA¡]5 nm¡^/ NPB¡]60-Y¡^nm¡^/NPB¡GAlq3 (Z wt%)(Y nm) / Alq3¡]60 nm¡^/ LiF(0.7 nm)/ Al(180 nm)) is decreased obviously. This result suggests that NPB¡GAlq3 layer could delay the holes mobility. The optimum concentration in our device is 30 wt% while the total thickness is 30nm. Then we combined NPB and Rubrene to obtaine white emission and fabricate a white organic light emitting diode (WOLED). The structure of WOLEDs is ITO/ MTDATA/ NPB/ NPB:Rubrene/ TPBI/ LiF/ Al. By change the concentration of NPB:Rubrene layer, the WOLED can emit white light. We can get the maximum luminance efficiency of 9.0 cd/A at 20.8mA/cm2 with 1 wt%. And the device emit greenish-white.
In order to get higher efficiency and pure light WOLED, we use the grading structure to prepare OLED. The structures are device A: ITO/ MTDATA(5nm)/ NPB(10nm)/ NPB:Rubrene1%(25nm)/ NPB:Rubrene 0.5%(25nm)/ TPBI(60nm)/ LiF(0.7nm)/Al (180nm); device B: ITO/ MTDATA(5nm)/NPB(10nm)/NPB:Rubrene2%(17nm)/ NPB:Rubrene1% (17nm)/NPB:Rubrene0.5%(17nm)/TPBI(60nm)/ LiF(0.7nm)/ Al (180nm)
We get the maximum luminance of 17270 cd/m2 and 24280 cd/m2 , respectively and the optimum efficiency of 16.1 cd/A and 18.5 cd/A, respectively. The CIE coordinate of the device is x=0.35, y=0.36, which is identical to white light.
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Measurements in the fundamentals of arithmetic ...Foran, Thomas George, January 1926 (has links)
Thesis (Ph. D.)--Catholic University of America, 1926. / Published also as Catholic University of America. Educational research bulletins ... vol. I, nos. 4-5. Bibliography: p. 71-74.
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A study of marks and marking systems in high school and in universityWooden, Walter Julius January 1924 (has links)
No description available.
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An analysis of the efficiency of teachers in rating pupilsHoladay, Perry W. (Perry Ward) January 1926 (has links)
No description available.
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Trends in marking systemsWilson, Glenn, 1907- January 1940 (has links)
No description available.
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An investigation of belt speeds and densities used in manual quality picking of small objectsOlivares, Carlos 12 1900 (has links)
No description available.
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An investigation of hand quality picking of small objectsZimmer, Hans Richard 08 1900 (has links)
No description available.
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Investigations leading to the establishment of grades for dried foodsLau, Shiu Chi 06 1900 (has links)
Graduation date: 1941
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Relationship between visual grades and instrumental color determinations of frozen strawberriesShah, Jayantilal Nemchand 08 May 1953 (has links)
Graduation date: 1953
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The transformation of reporting practices in one primary school context /Powell, Sharon Lee. Unknown Date (has links)
Thesis (MEd)--University of South Australia, 1995
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