色纯度改进的苯乙烯衍生物高效蓝色有机电致发光器件

Highly Efficient Distyryl Arylene (DSA) Derivative Blue Organi c Electroluminescent Device with Improved Color Purity

以苯乙烯衍生物 (amino substituteddistyrylarylenederivative,BCzVB)掺杂的 4 ,4′ 双 (9 咔唑基 ) 1,1′ 联苯(4 ,4′ N ,N′ dicarbazole biphyenyl,CBP)为发光层 ,制备了结构为ITO (indiumtinoxide) /TPD (N ,N′ diphenyl N ,N′ bis(3 methylphenyl) 1,1′biphenyl 4 ,4′diamine) /CBP :BCzVB/Alq3 [tris (8 hydroxy quinolinato)aluminum ) /Liq(8 hydroxy quinolinato) lithium]/Al的电致发光器件。这里TPD、Alq3 分别为空穴传输层和电子传输层 ,CBP :BCzVB为发光层 ,Liq为电子注入层。器件最高亮度为 85 0 0cd/m2 ,效率为 3.5cd/A (量子效率为 2 .6 % ) ,器件色坐标 [CommissionInternationaledel′Eclairage (CIE)co ordinates]为x =0 .15 ,y =0 .16 ,与纯BCzVB作发光层的器件相比 ,器件的发光色纯度和效率得到大幅提高。光致发光与电致发光对比分析表明器件的发光主要来自能量传递和陷阱俘获机制 ,但陷阱俘获机制起了主导作用。

An efficient pure blue multilayer organic ligh t-emitting-diode employing amino-substituted distyryl arylene derivative (DSA amine, BCzVB) doped into 4,4′-N,N′-dicarbazole-biphyenyl (CBP) is reported. The device structure is ITO (indium tin oxide)/TPD (N,N′-diphenyl-N,N′-bis (3-methyl-phenyl)-1,1′biphenyl-4,4′diamine)/CBP:BCzVB/Alq 3 [tris-(8-hydroxy-quinolinato) aluminum]/Liq(8-hydroxy-quinolinato lithium)/Al, here TPD is used as a hole transporting layer, CBP as a blue emitting host, BCzVB as a blue dopant, Alq 3 as an electron transporting layer, Liq as an electron injection layer, and Al as the cathode, respectively. Maximum luminance of 8500 cd/m2, and the device efficiency of 3.5 cd/A (quantum efficiency is 2.6%) are achieved. Commission Internationale de l'Eclairage (CIE) co-ordinates are x=0.15, y=0.16. In comparison with the neat BCzVB device, the efficiency and color purity of the doped device are significantly improved. Analysis of photoluminescence and electroluminescence shows that the luminescence of the device comes from Foster energy transfer and carrier trapping mechanism, but the carrier trapping is the main mechanism for exciton formation on BCzVB molecules under the electrical excitation.