A convenient and improved procedure has been developed for preparing the red fluorophore N-methyl-bis(4-(N-(1-naphthyl)-N-phenylamino)phenyl)maleimide (NPAMLMe) through the efficiently synthesized bis(4-bromophenyl)fumaronitrile, the necessary precursor in preparing NPAMLMe. This allows NPAMLMe to be an easily accessible material compared with other known red, organic light-emitting diode (OLED) materials. We also report an unusual approach in fabricating red OLEDs, which does not adopt a conventional red dopant but rather NPAMLMe as the host red emitter. The performance of the non-doped red devices has been studied in depth for the first time. Devices with varied layer thickness were fabricated for examining the compatibility of NPAMLMe with commonly known materials, electron-transporting tris(8-hydroxyquinolinolato)aluminium (Alq3) and hole-transporting 4,4′-bis(4-(N-(1-naphthyl)-N-phenylamino)phenyl)biphenyl (NPB). In the presence of a hole-blocking layer of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), the devices emit pure red electroluminescence (EL), and it is essentially voltage-independent. Red EL with a brightness near 4600 cd m−2 and an external quantum efficiency as high as 1.6% has been achieved. The performance of such non-doped, red OLEDs is comparable with or better than contemporary, dopant-based, red OLEDs, and the simple fabrication is the advantage of the approach.
                                    一种方便且改进的程序已被开发用于制备红色荧光体N-甲基-双(4-(N-(1-
萘基)-N-苯基
氨基)苯基)马来
酰亚胺(NP
AMLMe),该程序通过高效合成的双(4-
溴苯基)
呋喃腈,这是一种制备NP
AMLMe所需的前驱体。这使得NP
AMLMe与其他已知的红色有机发光二极管(OLED)材料相比,成为一种易于获取的材料。我们还报告了一种不寻常的红色OLED制造方法,该方法没有采用传统的红色掺杂剂,而是将NP
AMLMe作为主红色发射体。首次对非掺杂红色器件的性能进行了深入研究。制造了不同层厚度的器件,以考察NP
AMLMe与常见材料的兼容性,包括电子传输材料三(
8-羟基喹啉)铝(Alq3)和孔传输材料4,4′-双(4-(N-(1-
萘基)-N-苯基
氨基)苯基)
联苯(NPB)。在2,9-二甲基-4,7
-二苯基-1,10-
菲啰啉(
BCP)的孔阻挡层存在下,器件发出纯红色电致发光(EL),并且基本上与电压无关。实现了接近4600 cd m−2的亮度和高达1.6%的外量子效率。这种非掺杂红色OLED的性能与当代掺杂型红色OLED相比可媲美或更佳,同时简化的制造过程也是该方法的优势。