國立高雄大學圖資館 |

Language: English

Back

OLEDs: Light Extraction and Deep Blu...

Hippola, Chamika.

OLEDs: Light Extraction and Deep Blue Emission.

Record Type:	Electronic resources : Monograph/item
Title/Author:	OLEDs: Light Extraction and Deep Blue Emission.
Author:	Hippola, Chamika.
Published:	Ann Arbor : ProQuest Dissertations & Theses, 2019
Description:	132 p.
Notes:	Source: Dissertations Abstracts International, Volume: 81-04, Section: B.
Notes:	Advisor: Shinar, Joseph;Shinar, Ruth.
Contained By:	Dissertations Abstracts International81-04B.
Subject:	Condensed matter physics.
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=22583190
ISBN:	9781088335567

OLEDs: Light Extraction and Deep Blue Emission.
Hippola, Chamika.

OLEDs: Light Extraction and Deep Blue Emission. - Ann Arbor : ProQuest Dissertations & Theses, 2019 - 132 p.

Source: Dissertations Abstracts International, Volume: 81-04, Section: B.

Thesis (Ph.D.)--Iowa State University, 2019.

This item must not be sold to any third party vendors.

OLEDs have emerged in the market over the last decade mainly in display applications due to their unique and attractive properties, such as lightweight, high brightness with strong color contrast, thin and flexible designs as well as potentially of low cost. OLEDs for lighting applications are under extensive research and development. Though promising for solid-state lighting, there are critical aspects that need to be addressed to increase their efficiency, which will lead to commercialization.One major issue is the ~20% OLEDs’ limited forward outcoupling efficiency. This is due to several loss processes. More specifically, light generated in the emissive layer is internally trapped/ waveguided in the substrate or lost to surface plasmon excitation at the metal cathode. Another issue is the less efficient and unstable blue, especially deep blue (400–450 nm), OLEDs.This dissertation addresses both of these key OLED issues.The outcoupling efficiency that is limited by the internal/ external waveguiding along with surface plasmon excitation loss was enhanced by using novel corrugated plastic substrates. The unique substrate structure enables enhanced outcoupling in the forward hemisphere by minimizing total internal reflection and surface plasmon excitation. The dissertation demonstrates OLEDs with an external quantum efficiency of 50%, meaning an outcoupling efficiency ≥ 50% for a green phosphorescent OLEDs which yields a > 2-fold enhancement over the conventional flat devices. Enhancements were observed for blue and white phosphorescent devices depending on the pitch of the corrugation and the features’ height.Bright (14000 cd/m2) deep blue TADF exciplex-based OLEDs were fabricated using low cost abundant commercial organic small molecules, including triphenylphosphine oxide (PPh3O). The deep blue emission peaked at ~435 nm with the peak emission credited mainly to triplet exciplex emission at NPB/TPBi:PPh3O 5:1 interface. The triplet emission was confirmed by the strong quenching of the phosphorescence of the emitting layer in the presence of O2.

ISBN: 9781088335567Subjects--Topical Terms:

708726
Condensed matter physics.
Subjects--Index Terms:

Bright deep blue OLEDs

OLEDs: Light Extraction and Deep Blue Emission.
LDR:03280nmm a2200385 4500 001 594517
005 20210521101644.5
008 210917s2019 ||||||||||||||||| ||eng d
020 $a 9781088335567
035 $a (MiAaPQ)AAI22583190
035 $a AAI22583190
040 $a MiAaPQ $c MiAaPQ
100 1 $a Hippola, Chamika. $3 886503
245 1 0 $a OLEDs: Light Extraction and Deep Blue Emission.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2019
300 $a 132 p.
500 $a Source: Dissertations Abstracts International, Volume: 81-04, Section: B.
500 $a Advisor: Shinar, Joseph;Shinar, Ruth.
502 $a Thesis (Ph.D.)--Iowa State University, 2019.
506 $a This item must not be sold to any third party vendors.
520 $a OLEDs have emerged in the market over the last decade mainly in display applications due to their unique and attractive properties, such as lightweight, high brightness with strong color contrast, thin and flexible designs as well as potentially of low cost. OLEDs for lighting applications are under extensive research and development. Though promising for solid-state lighting, there are critical aspects that need to be addressed to increase their efficiency, which will lead to commercialization.One major issue is the ~20% OLEDs’ limited forward outcoupling efficiency. This is due to several loss processes. More specifically, light generated in the emissive layer is internally trapped/ waveguided in the substrate or lost to surface plasmon excitation at the metal cathode. Another issue is the less efficient and unstable blue, especially deep blue (400–450 nm), OLEDs.This dissertation addresses both of these key OLED issues.The outcoupling efficiency that is limited by the internal/ external waveguiding along with surface plasmon excitation loss was enhanced by using novel corrugated plastic substrates. The unique substrate structure enables enhanced outcoupling in the forward hemisphere by minimizing total internal reflection and surface plasmon excitation. The dissertation demonstrates OLEDs with an external quantum efficiency of 50%, meaning an outcoupling efficiency ≥ 50% for a green phosphorescent OLEDs which yields a > 2-fold enhancement over the conventional flat devices. Enhancements were observed for blue and white phosphorescent devices depending on the pitch of the corrugation and the features’ height.Bright (14000 cd/m2) deep blue TADF exciplex-based OLEDs were fabricated using low cost abundant commercial organic small molecules, including triphenylphosphine oxide (PPh3O). The deep blue emission peaked at ~435 nm with the peak emission credited mainly to triplet exciplex emission at NPB/TPBi:PPh3O 5:1 interface. The triplet emission was confirmed by the strong quenching of the phosphorescence of the emitting layer in the presence of O2.
590 $a School code: 0097.
650 4 $a Condensed matter physics. $3 708726
650 4 $a Electrical engineering. $3 454503
650 4 $a Materials science. $3 221779
653 $a Bright deep blue OLEDs
653 $a Corrugated OLEDs
653 $a Enhanced outcoupling
653 $a OLED
653 $a Surface plasmon mitigation
653 $a TADF exciplex OLEDs
690 $a 0611
690 $a 0544
690 $a 0794
710 2 $a Iowa State University. $b Physics and Astronomy. $3 886504
773 0 $t Dissertations Abstracts International $g 81-04B.
790 $a 0097
791 $a Ph.D.
792 $a 2019
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=22583190