利用銅薄膜及基板製作上發光型有機發光二極體

Top emission organic light emitting diodes by using Copper thin-film orsubstrate as thermal dissipation material.

林柏榕(Po-Jung Lin)

指導教授 ： 蔡裕勝

共同指導教授 ： 莊賦祥(Fuh-Shyang Juang)

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2008年)

摘要

本研究元件結構先以玻璃基板Al (75nm )/ Au (2 nm)/ m-MTDATA (15 nm)/ NPB ( 30 nm)/ Alq3 (60 nm)/ LiF (0.5 nm)/ Al (2 nm)/ Ag (14 nm)先針對不同NPB的厚度找出最佳膜厚( NPB 30 nm)。然後將其元件結構製作在PET/ITO的背面與PET/ITO (蝕刻掉ITO)做為比較。再調變Alq3的膜厚( Alq3 55 nm)可獲的較佳的發光亮度及效率的提升。在9 V 時有最大亮度 2060 cd/m2 ，在 55 mA/cm2時有最大效率3.5 cd/A。
接著研究於PET/ ITO基板的背面製作可撓式上發光型有機光二極體，並調變陽極金屬Al的膜厚( 70~80 nm)以獲得最佳的發光亮度及效率。接著以Cu/ Al/ Au作為陽極金屬，利用Cu具高散熱的特性，以降低元件操作於高電流密度下，產生之焦耳熱對元件所造成之影響。實驗結果顯示，當陽極結構為Cu (30 nm)/Al (70 nm)/Au (2 nm)時，於11 V時元件有最大發光亮度 6100 cd/m2。而當陽極結構為Cu (20 nm)/Al (70 nm)/Au (2 nm)時，於10 V時元件有最大發光效率可達5.63 cd/A。
最後於銅散熱基板上旋塗LED UV膠為絕緣層以製造上發光型有機發光二極體，本研究利用旋轉塗佈LED膠作為絕緣層於研磨過的銅基板(39×39×1 mm)上，以製作上發光型有機光二極體。利用Cu基板具高散熱的特性，以降低元件操作於高電流密度下，產生之焦耳熱對元件所造成之影響。結果顯示，當LED膠轉速為4000 RPM (20 sec)時有最佳的亮度與效率分別為11700 cd/m2與3.39 cd/A，且當元件操作在高電流密度下，能有效的散逸熱能，並大幅提升元件的穩定性。

關鍵字

散熱

並列摘要

The organic light emitting diodes（OLED) is a new-generation flat panel display with the advantages of self-luminescence, wide viewing angle ( >170°), prompt response time ( ~1 μs), low operating voltage ( 3~10 V), high luminance efficiency, high color purity, and easy to be made on various substrates. In the recent years, OLED monitors have been getting larger and larger. These large monitors need to be driven by Thin Film Transistors (TFTs) to have even brightness, higher resolution and longer life. Traditional OLED resolutions are mostly in bottom emission structure and tend to be blocked by bottom TFTs and Data Line, affecting the penetration portion of rays to the bottom. To enhance the opening rate, top emission OLED (TEOLED) researches become inevitable. Moreover, the TEOLED is made on glass substrate via the process of thermal-evaporating, but being made on plastic substrate will make TEOLED become light, thin and flexible. Hence, TEOLED which is made on plastic substrate will be a future trend. In addition, the study employed inserting the high heat dissipation coefficient of Cu metal into the multi-layers anode, to discuss the heat dissipating impression on the characteristics of device.
This study used the device’s of Glass Al (75nm )/ Au (2 nm)/ m-MTDATA (15 nm)/ NPB ( 30 nm)/ Alq3 (60 nm)/ LiF (0.5 nm)/ Al (2 nm)/ Ag (14 nm),find the best thickness of NPB (30 nm).The device’s was fabricated on the reverse side of PET/ITO substrate and PET/ITO (etching ITO). The luminance and efficiency were improved after optimizing the thickness of electron transport material structure Alq3 (55 nm), the maximum luminance was 2060 cd/m2 at 9V and the maximum luminance efficiency was 3.5 cd/A at 55 mA/cm2.
This study made a flexible Organic Light Emitting Diode (OLED) on the back side of PET/ITO substrate successfully to avoid the uneven surface of device due to incomplete etching which can affect the luminance characteristic of device. Then the study added metal Cu into the multi-layers metal anode to improve heat dissipation effect of device and improve luminance characteristic of the device. When structure of device is PET/ITO (Backside)/ Cu (20 nm)/ Al (70 nm)/ Au (2 nm)/ m-MTDATA (15 nm)/ NPB (30 nm)/ Alq3 (60 nm)/ LiF (0.5 nm)/ Al (2 nm)/ Ag (14 nm), device will have the maximum luminance efficiency up to 5.63 cd/A @ 11 V. When structure of device is PET/ITO (Backside)/ Cu (30 nm)/ Al (70 nm)/ Au (2 nm)/ m-MTDATA (15 nm)/ NPB (30 nm)/ Alq3 (60 nm)/ LiF (0.5 nm)/ Al (2 nm)/ Ag (14 nm), device will have the maximum luminance up to 6100 cd/m2 @ 11 V
In this study, the OLED devices are fabricated on Cu substrates (39×39×1 mm). Before depositing the metal anode, ultrasonically cleaning the substrate in proper order with neutral cleaning agent (8 minutes), methanol (8 minutes) and de-ionized water (DI-Water) (8 minutes); then, we dried it via blowing nitrogen and put it into oven for roasting at 90 °C for 10 minutes. Nest, the LED UV glue was coated under the Cu substrate by spin-coating and curing by UV light for 20 seconds.This research has LED glue rotated and applied as isolation layer onto ground Cu substrate (39×39×1 mm) to make top emission OLED. The feature of high radiation of Cu substrate reduces the impacts of joule heat from devices operated under high current density. At rotation speed of LED glue of 4000 RPM (20 sec), we have best luminance and performance at 11700 cd/m2 and 3.39 cd/A. The devices operation under high current density, can effectively dissipating heat and significantly improving the stability of devices.

並列關鍵字

Thermal dissipation

參考文獻

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