通过拓展D-π-A结构中的π桥实现高效紫蓝光有机发光器件(CIEy=0.046)

Achieving Efficient Violet-blue Organic Light Emitting Devices(CIEy=0.046)by Extendingπ-conjugation in D-π-A Structure

紫蓝光有机发光材料在全彩显示和照明领域具有广阔的应用前景。但是该类材料需要宽能隙,因此开发高效的紫蓝色材料是一项巨大的挑战。本文利用10H-吩噻嗪5,5-二氧化物(2OPTZ)作为弱受体、N-苯基-2-萘胺(PNA)作为供体,设计合成了两个具有D-π-A型结构的紫蓝色材料,命名为2OPTZ-PNA和2OPTZ-BPPNA。通过延长给受体之间的π共轭长度,使局域态和电荷转移态被优化,并且薄膜中的绝对量子产率从14%提高到33%。此外,利用2OPTZ-BP-PNA制备的非掺杂器件呈现紫蓝光(436 nm)发射,半峰全宽为54 nm,色坐标为(0.155,0.046),外量子效率为4.1%。鉴于此,本文提供了一种制备高质量紫蓝发光材料的有效策略。

Organic violet-blue luminescent materials have exhibited great potential in full-color displaying and lighting fields.However,it is a huge challenge to develop efficient violet-blue emitters because of the inherently wide energy gap.In this work,two violet-blue emitters with donor(D)-π-acceptor(A)type using 10H-phenothiazine 5,5-dioxide(2OPTZ)as a weak acceptor and N-(2-naphthyl)aniline(PNA)as the donor,namely 2OPTZ-PNA and 2OPTZ-BPPNA,were designed and synthesized.By extendingπ-conjugation length between donor and acceptor,local excited states and charge transfer excited states were adjusted,and absolute photoluminescence quantum yields(PLQYs)values in the evaporated film increased from 14% to 33%.Notably,non-doped device based 2OPTZ-BP-PNA exhibits violetblue light at 436 nm with a narrow full width at half-maximum(FWHM)of 54 nm,Commission Internationale de l’Eclairage(CIE)coordinates of(0.155,0.046)and external quantum efficiency(EQE)of 4.1%.Given this,our results provide an efficient design strategy for the high-quality violet-blue luminescent materials.