Study On The Preparation And Luminescent Properties Of Organic Semiconductors Containing Phenothiazine And Oxadiazole Units

The molecular design, synthesis and the applied research in organic light emitting device (OLED) of organic semiconductor materials have been one hotspot in recent years. By changing or modifying the structures of organic semiconductor materials it can easily adjust the energy level, the transfer type, and other properties of OLED. The dissertation is divided into four chapters.(1) Three small molecular electroluminescent materials of phenothiazine derivatives (PTH-I, PTH-II, PTH-III) were designed and synthesized. Their physical and chemical properties were analyzed by UV-vis, PL, CV, EL methods. Furthermore, the single/double devices fabricated by PTH-I, PTH-II, PTH-III were studied primarily.(2)The PPV-type polymer containing phenothiazine and oxadiazole unit (P-PT-OXA-EH) was designed and investigated. The polymeric yield is 34.20 %; Mn=8.6296e3, Mw=1.1355e4, Tdc=352 oC (indicating that P-PT-OXA-EH has a good heat stability). The introduction of alkyl (-OC12H25, -EH) to the side chain can greatly enhance the solubility of the light emitting material. Furthermore, the luminescent characteristics of devices [ITO/P-PT-OXA-EH/Ca/Ag having different P-PT-OXA-EH contents with 1.0 % (PT-A), 0.5 %(PT-B), 0.3 %(PT-C) respectively] were studied thoroughly. Their threshold voltages are 20 v, 10 v and 5 v, and maximum brightness are 300(30 v), 800(20 v), 2000 cd/m2 (15 v) respectively. To device of PT-C, the luminescent brightness is 2000 cd/m2 with current intensity 47.5 mA, which is ten times than that of a single PPV-fabricated device.(3) The polymer containing oxadiazole unit (P-OXA-II) was synthesized successfully by Wittig-Horner method. The luminescent properties of the device (ITO/P-OXA-II(0.5 %)/Ca/Ag) were studied carefully. The peak values of PL and EL are 530 nm (Ex: 450 nm) and 545 nm with green light.(4) The non-conjugated type polymer---poly(arylene ether) containing oxadiazole unit (P-E-I) was designed and synthesized for the first time. The yield is 92.10 %, Mn=8.1889e3, Mw=3.3306e4. The polymer possesses good heat stability and solubility. The device (ITO/P-E-I/Ca/Ag) was fabricated with peak value 428 nm emitting blue light.