摘要
有机发光二极管（OLED）因具有效率高、自发光、种类多样、能耗低、制造成本低、又轻又薄、发光谱域宽、无视角依赖性等一系列独特优点而引起广大科学家的极大关注。微腔可以窄化有机发光二极管出射光谱,提高有机发光二极管的色饱和度。以玻璃为衬底,金属Ag薄膜作为器件阳极金属反射镜,NPB为空穴载流子传输材料,Alq3为发光材料和电子载流子传输材料,Al膜作为器件阴极金属反射镜,制作了结构是衬底/Ag（15nm）/MoO3（xnm）/NPB（50nm）/Alq3（60nm）/Al（100nm）的A,B,C和D四种类型的微腔有机发光二极管,其中：A,x=4nm;B,x=7nm;C,x=10nm;D,x=13nm。在电压13V时,器件A,B,C,D的亮度分别达到928,1 369,2 550和2 035cd·m-2。在电流密度60mA·cm-2时,A,B,C,D器件的电流效率分别达到2.2,2.6,3.1和2.6cd·A-1。实验结果表明,在有机微腔发光二极管内部,电子为多数载流子,空穴是少数载流子。MnO3薄膜在4~10nm的厚度范围,能够极大地增强器件空穴的注入能力。并且,随着MnO3薄膜厚度的增加,空穴注入能力不断增大。
Organic Light Emitting Diodes（OLEDs）has been a promising new research point that has received much attention recently.Emission in a conventional OLED originates from the recombination of carriers（electrons and holes）that are injected from external electrodes.In the device,Electrons,on the other hand,are injected from the Al cathode to an electron-transporting layer and travel to the same emissive zone.Holes are injected from the transparent ITO anode to a hole-transporting layer and holes reach an emitting zone through the holetransporting layer.Electrons and holes recombine at the emissive film to form singlet excited states,followed by emissive light.It is because OLED is basically an optical device and its structure consists of organic or inorganic layers of sub-wavelength thickness with different refractive indices.When the electron and holes are injected through the electrodes,they combine in the emission zone emitting the photons.These photons will have the reflection and transmission at each interface and the interference will determine the intensity profile.The emissive light reflected at the interfaces or the metallic electrode returns to the emissive layer and affects the radiation current efficiency.Microcavity OLED can produce saturated colors and narrow the emission spetrum as a new kind of technique.In the paper,we fabricate microcavity OLED using glass substrate.Ag film acts as the anode reflector mirror;NPB serves as the hole-transporting material;Alq3is electron-transporting material and organic emissive material;Ag film acts as cathode reflector mirror.The microcavity OLED structures named as A,B,C and D are glass/Ag（15nm）/MoO3（xnm）/NPB（50nm）/Alq3（60nm）/Al（100nm）.Here,A,x=4nm;B,x=7nm;C,x=10nm;D,x=13nm.The characteristic voltage,brightness and current of these devices are investigated in the electric field.The luminance from the Devices A,B,C and D reaches the luminance of 928,1 369,2 550and2 035cd·m-2,respectively at 13 V.At 60mA·cm-2,the current efficiency of the microcavity OLEDs using MnO3 are about2.2,2.6,3.1and 2.6cd·A-2 respectively.It is found that electrons are majority carriers and holes are minority carriers in this microcavity OLEDs.MnO3 film can improve hole injection ability from 4to 10 nm.In addition,hole injection ability is increased with the increasing thickness of the MnO3 film.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2016年第3期648-652,共5页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(60806047)
重庆市自然科学基金项目(CSTC2015jcyjA70001
CSTC2015jcyjBX0032)
重庆市科技人才培养计划项目(cstc2013kjrc-qnrc90003)
重庆市教委科学技术研究项目(KJ1400509)
重庆市教委教改项目(yigl23100)
首批重庆市高等学校青年骨干教师资助计划项目(53)
重庆师范大学教改项目(cyjg1219)
重庆高校创新团队建设计划项目(201013)资助
