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 life-time). In measuring

the measurement software simultaneously controls Keithley-2400 Source Meter and Keithley-485 Picoammeter which can get device-current value and photo-current value respectively via data-acquisition board

then transfers device-current value and photo-current 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: Voltage-Current Curve

Voltage-Photocurrent Curve and Quantum Efficiency-Current 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 MEH-PPV with orange light emitting. This sample device's quantum efficiency value can reach 0.39% under 17V.