超薄层在白色有机电致发光器件中的应用  

Application of Ultrathin Layer in White Organic Electroluminescent Devices

作　　者：邓召儒[1] 杨盛谊[1] 孟令川[1] 娄志东[1] 

机构地区：[1]北京交通大学光电子技术研究所,发光与光信息技术教育部重点实验室,北京100044

出　　处：《物理化学学报》2008年第4期700-704,共5页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(60406006,60777025和10434030);教育部新世纪优秀人才支持计划(NCET-06-0077);北京市自然科学基金(2062019);北京市科技新星计划(2006B20)资助

摘　　要：以DCJTB为掺杂剂,以BCP为空穴阻挡层,研究了两种结构的有机电致发光器件ITO/NPB/BCP/Alq3∶DCJTB/Alq3/Al(结构A)和ITO/NPB/BCP/Alq3/Alq3∶DCJTB/Alq3/Al(结构B)的电致发光光谱.实验结果显示,在结构A器件的电致发光光谱中,绿光的相对发光强度较弱,增加Alq3层的厚度对绿光的相对发光强度的影响也很小;而在结构B器件的电致发光光谱中,BCP层与掺杂层(Alq3∶DCJTB)之间的Alq3薄层对绿光的相对发光强度影响显著,用很薄的Alq3层就可以得到强的绿光发射.进一步改变器件结构,利用有机超薄层就可以得到稳定的白光器件ITO/NPB(50nm)/BCP(3nm)/Alq3(3nm)/Alq3∶DCJTB(1%(w))(5nm)/Alq3(7nm)/Al.随着电压的增加(14-18V),该器件的色坐标基本保持在(0.33,0.37)处不动;在432mA·cm-2的电流密度下,该器件的发光亮度可达11521cd·m-2.Based on 4-（dicyanomethylene）-2-t-butyl-6-（1,1,7,7-tetramethyljulolidyl-9-enyl）-4H-pyran （DCJTB） acting as dopant and 2,9-dimethyl-4,7-diphenyl-l,10-phenanthroline （BCP） acting as hole-blocking layer, the EL spectra of two kinds of organic light-emitting diodes （OLEDs） ITO/NPB/BCP/Alq3∶DCJTB/Alq3/Al （structure A） and ITO/NPB/BCP/Alq3/Alq3∶DCJTB/Alq3/Al （structure B） were investigated. Our experimental data showed that the relative emission intensity of green light was low in the EL spectra of devices with structure A, and it was hard to enhance the relative emission intensity of green light by only increasing the thickness of Alq3 layer. On the other hand, the thin layer of Alq3 inserted between BCP layer and dopant layer （Alq3：DCJTB） had a tremendous impact on the relative emission intensity of green light for devices with structure B, and a strong green light emission could be obtained by inserting an ultrathin layer of Alq3. Further, by optimizing the device structure, a stable white OLED ITO/NPB（50nm）/BCP（3nm）/Alq3（3nm）/Alq3∶DCJTB（1%（w））（5nm）/Alq3（7nm）/Al was obtained with ultrathin organic layers of BCP, Alq3 and Alq3：DCJTB. The CIE of the device almost kept at （0.33, 0.37） with increasing the applied voltages （14-18 V）, and its luminance reached 11521 cd·m^-2 at the current density of 432 mA·m^-2.

关 键 词：白色有机电致发光器件 超薄层 空穴阻挡层 

分 类 号：TN383.1[电子电信—物理电子学]