氧化锌锡作为电子传输层的量子点发光二极管

本文研究了以胶状量子点作为发光层和有机/无机混合材料作 为电子-空穴传输层的电致发光二极管器件. CdSe 量子点以薄膜的形式夹在无机氧化锌锡电子传输层和有机TPD空穴传输层中间构成三明治结构. 氧化锌锡电子传输层采用磁控溅射实现, 有机TPD空穴传输层和量子点发光层则采用旋涂的方法制备, 得到的QD-LEDs器件结构界面陡峭、表面平整. 光电特性表征结果显示器件的电致发光具有良好的单色性、低的开启电压, 利 用具有高电子迁移率和低载流子浓度的无机氧化锌锡薄膜作为电子传输层可 以实现器件在大气环境下稳定、明亮的电致发光. 本文分析了器件的工作机理并通过改变氧化锌锡的电导率达到控制器件中电子和空穴的注入比的目的, 优化了器件的光电性能. 关键词： 量子点 氧化锌锡 电致发光 电子传输层

QD-LED devices using ZnSnO as an electron-transporting layer

We have investigated the light-emitting diodes based on colloidal CdSe quantum dots (QD-LEDs), in which inorganic ZnSnO thin films and organic TPD thin films were used as the electron-transporting layer (ETL) and hole-transporting layer (HTL), respectively. The quantum dots were embedded between the inorganic ETL and organic HTL to form a sandwich structure. ZnSnO ETL was made by magnetron sputtering, while the TPD and QD films were made by spin-coating method. The QD-LEDs display sharp interface and smooth morphology. Optical and electrical characterizations show that QD-LEDs have low turn-on voltage, good monochromaticity, bright electroluminescence and good stability in atmosphere ambient. These characteristics are attributed to the utility of high electron mobility and low carrier concentration of the ZnSnO films used as the ETL. To investigate the device’s operation mechanism, the conductivity of ZnSnO was varied during deposition to realize equal injection rate for both electrons and holes, which allows the device to operate optimally.
Keywords： quantum dots ZnSnO electroluminescence electron-transporting layer