Study On The Establishment Of The Quantum Efficiency Measurement System And The Enhancement Of Quantum Efficiency Value Of Organic Light-Emitting Diodes

Recently the organic light-emitting diodes (OLED) provided with excellent performance has become a predominant contestant in most flat display technology. Although the OLED technology has been well developed, some luminescent performance of it, such as life-time, quantum efficiency etc, is not ideal which restrict its practicability. All factors that affected the luminescent performance of OLED were analyzed in this paper. We have designed and established a measurement system which can measure various OLED's quantum efficiency value and found some available methods to enhance the quantum efficiency value and luminescent performance of OLED .1. On account of enhancing OLED's quantum efficiency must be the basic precondition which imposed by accurately measuring device's quantum efficiency , therefore , we have designed and established an quantum efficiency measurement system mainly composed by a series of components which produced by Keithley Corporation. Furthermore, in order to prove the availability of this measurement system, we have applied the system to measuring a sample device which contains MEH-PPV with orange light emitting. The results we got accords to relevant reports perfectly.2. We applied the quantum efficiency measurement system to test the OLED cell which has a three-layer structure [ITO/MEH-PPV/A1]. According to the measurement results, we found the key point by studying the matching of energy levels and balance injection of carriers. As a result, Ca was used as the cathode of OLED cell [ITO/MEH-PPV/Ca/Al] whose quantum efficiency value and luminescent performance were enhanced greatly.3. Some pilot study has been carried through on the electroluminescent characteristics of a new chelate-metal complex L₁AgClO₄ in primary content of the fifth chapter. And, we applied the quantum efficiency measurement system to test the OLED cell which has a three-layer structure [ITO/L₁AgClO₄/Al]. After analyzing the measurement results and fabrication technics,we made a breakthrough at film-formation and carriers transport characteristics. In the blend-layer OLED, PVK plays a important role in enhancing quantum efficiency value and luminescence performance of OLED cell which has a three-layer structure [ITO/ PVK: L₁AgClO₄/Al]. Finally we concluded the measurement results according to with our prediction.