Improved blue emission through multi-layer structure and material purification

摘要

The blue emission from organic electroluminescent device was successfully improved through the fine purification process of material and the multi-layer structure including hole injection layer, hole transport layer, hole blocking layer, and low work function cathode layer. The finely purified blue emitter was carefully examined to know the difference before and after purification by using absorption spectroscopy, photoluminescence spectroscopy, differential scanning calorimeter, and ultraviolet photoemission spectroscopy. The CIE color coordinate of x, y was 0.15, 0.08 at above 10,000 cd/m~2.