The Organic Light-emitting Devices Based On Hole Buffer Layer M-MTDATA

Organic light-emitting devices （OLED） have become a shining star in the electronic display field since the end of 1980s. This technology exhibits bright prospect in photo electricity field due to its advantages of low DC drive voltage, active luminescence, excellent hue saturation, wide visual angle, etc. Nowadays, small-area OLED have been commercially produced in the area of mobile meters, screen of mobile phones and digital cameras, etc. The performance of OLED have been improved significantly with the adoption of novel materials, suitable structures and process technologies. However, electroluminescent device efficiency, lifetime, driving voltage still need further improvement.The organic light emitting device （OLED） with the structure of ITO/Meo-TPD/Alq₃/LiF/Al were fabricated using Alq₃ as a light-emitting layer, After fabricating the device, testing its current - voltage （IV） characteristics, the brightness - voltage （BV） characteristics, electroluminescence spectra immediately at room temperature under atmospheric environment, using the PR-650 spectral luminance meter and U. S. Keithley-2400 voltage-current test system.The operating voltage of device was about 10V, its maximum brightness reacheed 13400cd/m2, when the applied voltage was 16V. When the applied voltage was 8V, the electroluminescence spectra peak was at 528nm , showing green. The organic light emitting device （OLED） with the structure of ITO/ m-MTDATA/Meo-TPD/Alq₃/LiF/Al were fabricated using Alq₃ as a light-emitting layer, m-MTDATA as a hole injection buffer layer and Meo-TPD as a hole transport layer, as well as luminous and electrical properties were studied. The operating voltage of device was about 6V, its maximum brightness reached 14300cd/m2, with applied voltage of 13V, when the applied voltage was 8V, the electroluminescence spectra peak was at 540nm , showing green. Compared with measured data of the two devices, owing to m-MTDATA buffer layer, device brightness have been enhanced under lower voltage, and turn on voltage has been largely cut down.