基于颜色转换层的有机白光器件性能研究

Study on Performances for White Organic Light-emitting Device Based on Color Conversion Layer

以DCJTB为颜色转换层,结合双蓝色发光层有机电致发光器件制备了结构为PMMA∶DCJTB(x%)/ITO/NPB(30nm)/mCP(5nm)/mCP∶Firpic(8%,30nm)/TPBi∶Firpic(8%,10nm)/TmPyPB(30nm)/Cs2CO3(1.nm)/Al(x=0.7,1.0,1.5)的白色有机发光器件.结果表明,器件的效率和显示性可通过DCJTB浓度加以调控,当DCJTB浓度为1.0%时,器件拥有最佳性能,其最大电流效率、色坐标和显色指数分别为13.4cd·A^-1、(0.33,0.31)和69.为进一步提高器件效率和显色性,在发光层TPBi∶Firpic与电子传输层TmPyPB之间插入TPBi/TPBi∶Ir(ppy)3结构,研究表明:该插入结构能丰富器件发光颜色,增大颜色转换层的有效吸收光量;同时可限制激子复合区域,提升激子利用率,实现了器件效率和显色性能的同时提升.获得的白光器件最大电流效率和显色指数分别为17.8cd·A^-1和81,分别提升了33%和17%,色坐标仅漂移(0.02,0.02).

A White Organic Light-Emitting Device(WOLED) was realized by combining dual-emission blue organic light-emitting device of ITO/NPB(30 nm)/mCP(5 nm)/mCP∶Firpic(8%,30 nm)/TPBi∶Firpic (8%,10 nm)/TmPyPB(30 nm)/Cs 2 CO 3 (1.nm)/Al with color conversion layer based on PMMA∶DCJTB.Experimental results indicate that the current efficiency and Color Rendering Index(CRI) can be controlled by adjusting the concentration of DCJTB in color conversion layer.The maximum current efficiency,Commission Internationale de L′Eclairage(CIE) and CRI are 13.4 cd·A^-1,(0.33,0.31) and 69,respectively,when the concentration of DCJTB is 1.0%.To further improve the device performances,TPBi/TPBi∶Ir(ppy) 3 was inserted between the emission layer of TPBi∶Firpic and the electron transport layer of TmPyPB.It is illustrated that the inserted structure can improve the CRI,increase the effective absorption of color conversion layer,and limit the recombination region of excitons to enhance the optoelectronic performances of the device.The maximum current efficiency,CIE and CRI for optimal WOLED reach 17.8 cd·A^-1,(0.35,0.33) and 81,respectively.