氧化鋅奈米晶體引入乙氧基化聚乙烯亞胺/聚芴電解 質作為電子傳輸層以應用於含銫鈣鈦礦發光元件

ZnO nanocrystals incorporating PEIE/polyfluorene electrolyte as electron transport layers for cesium-containing perovskite light-emitting devices

張峻榮(Chun-Jung Chang)

指導教授 ： 楊勝雄

國立交通大學/光電學院/照明與能源光電研究所/碩士(2019年)

摘要

本研究提出以氧化鋅奈米晶體(ZnO NCs)作為電子傳輸層搭配溴化銫鉛(CsPbBr3)薄膜作為發光層之反結構鈣鈦礦發光元件。乙氧基化聚乙烯亞胺(polyethyleneimine ethoxylated, PEIE)與含有六氟磷酸根三甲基銨之聚芴電解質(取名為P2-PF6)引入ZnO奈米晶體與CsPbBr3薄膜之間以提升元件電子注入。PEIE/P2-PF6雙層的引入有效地改善CsPbBr3薄膜的覆蓋率以及表面型態以減少鈣鈦礦發光元件的漏電流。同時，經優化後的CsPbBr3薄膜具有更佳的光激發光，其歸因於PEIE/ P2-PF6雙層的抗淬滅能力以及增加的載子生命週期。於此，使用聚(9,9-二辛基芴-co-N-(4-丁基苯基)二苯胺) (TFB)作為電洞傳輸層，製作結構為ITO/ZnO NCs/PEIE/P2-PF6/CsPbBr3 film/TFB/Au之鈣鈦礦發光元件。引入PEIE/P2-PF6鈣鈦礦發光元件之驅動電壓為2.8 V，最大亮度為3,927 cd/m2，而最大電流效率為0.2 cd/A，均明顯優於不具PEIE/P2-PF6雙層之元件。

關鍵字

鈣鈦礦 ； 發光元件 ； 乙氧基化聚乙烯亞胺 ； 聚芴電解質 ； 氧化鋅

並列摘要

In this work, we demonstrate inverted perovskite light-emitting devices (PeLEDs) based on ZnO nanocrystals (NCs) and cesium lead bromide (CsPbBr3) film as the electron transport and emission layers, respectively. A polyethyleneimine ethoxylated (PEIE) and/or an ionic polyfluorene electrolyte containing trimethylammonium hexafluorophosphate groups (namely P2-PF6) were introduced between ZnO NCs and CsPbBr3 film to enhance electron injection. The introduction of the PEIE/P2-PF6 bilayer can effectively improve CsPbBr3 coverage and morphology, thereby reducing current leakage in PeLEDs. Meanwhile, the improved CsPbBr3 film showed better photoluminescence, owing to anti-quenching capability of the PEIE/P2-PF6 and prolonged carrier lifetime. Herein, the PeLEDs with the structure ITO/ZnO NCs/ PEIE/P2-PF6/CsPbBr3 film/poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenyl amine) (TFB)/Au were fabricated, employing TFB as the hole transport layer. The PeLED based on the PEIE/P2-PF6 showed a turn-on voltage of 2.8 V, a max luminance of 3,927 cd/m2 and max current efficiency of 0.2 cd/A that was significantly higher than those without PEIE/P2-PF6 bilayer.

並列關鍵字

perovskite ； PeLED ； ZnO ； PEIE ； polyfluorene electrolyte

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