摘要
有机电致发光器件(OLED)的量子效率是衡量器件发光性能的一个非常重要的参数。考虑到提高OLED量子效率的基本前提是能精确测得器件的量子效率,本文工作采用美国Keithley公司的系列产品,设计与组建了一套精确测量OLED量子效率的测量系统(主要由真空系统和测试系统组成)。应用本系统测量时,由测量软件通过数据采集卡来实时地对K 2400(稳压源)和K 485(微检流计)进行控制,得到流经器件的电流和器件输出的光电流,再经过换算得出注入器件的电子数和从器件输出的光子数,从而能够得到器件的量子效率值,最后由计算机动态地绘制出器件的性能曲线。此外,我们还利用本测量系统对以MEH PPV为基质的橙红色OLED进行了测量,该测试样品在0 0117A/cm2的电流密度下,测得量子效率为0 39%。
The quantum efficiency of organic light emitting diodes (OLED) is an extraordinary factor of device's luminescence performance. Here, quantum efficiency can be defined by the proportion of the number of photons (exports from device) to the number of electrons (imports into device) per second. On account of enhancing OLED's quantum efficiency, a measurement system must be the basic precondition which can be imposed to measure device's quantum efficiency accurately, therefore, we have designed and established an measurement system (with vacuum unit and measurement unit) which can accurately measure the OLED's quantum efficiency. This measurement system is mainly composed by a series of components which produced by Keithley Corporation. Placing the sample device on the silicon photodiodes before measurement, then the measurement room can be vacuumized (Vacuum environment can improve the device's stability and lifetime). In measuring, the measurement software simultaneously controls Keithley2400 Source Meter and Keithley485 Picoammeter which can get devicecurrent value and photocurrent value respectively via dataacquisition board, then transfers devicecurrent value and photocurrent value into the number of electrons and the number of photons, finally the quantum efficiency value can be concluded. At the same time, the computer can finish plotting the device's performance curves (such as : VoltageCurrent Curve, VoltagePhotocurrent Curve and Quantum EfficiencyCurrent Density Curve) according to the above values. Furthermore, in order to prove the availability of this measurement system, we have applied the system in measuring a sample device which contains MEHPPV with orange light emitting. This sample device's quantum efficiency value can reach 039% under 17V.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2002年第6期595-598,共4页
Chinese Journal of Luminescence
基金
国家自然科学基金(69976021)
天津市高校科技发展基金(990311)
天津市自然科学基金重点项目(023800511)
天津市材料物理与化学重点学科资助项目
