Improved Performance of Solution Processed Small Molecular Blue OLEDs through Thermal Annealing

• Main Authors: Yu-Cheng Chou, 周宥呈
• Other Authors: Wen-Yao Huang
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/qq5he5

碩士 === 國立中山大學 === 光電工程學系研究所 === 107 === 　　In this thesis, the three small-molecule organic luminescent materials synthesized in our laboratory were used as the emitting layer of the organic light-emitting diode. Analysis of three material films, including absorption, luminescence, energy level, and thermal stability. Among the three materials CzAnCz, AnCz, AnCzAn, CzAnCz has the least redshift, because Carbazole alcohol-containing derivatives provide higher steric hindrance, which can reduce the aggregation and stacking of materials. And all three materials has good thermal stability, Td5% is around 400 °C, and Tg is about 100 °C, CzAnCz has the best emission color, the theoretical CIE coordinates is (0.15, 0.06). 　　Since the three small molecular materials are solution processable, the organic light emitting diode was fabricated by spin coating. And in order to improve component performance, the light-emitting layer is modified by a film thermal annealing treatment commonly used in a wet process, and it is desired to enhance the photoelectric properties of the film by rearranging the molecules to obtain a high-efficiency, high-luminance device. 　　The OLED structure used in this study is ITO/PEDOT:PSS/CzAnCz or AnCz or AnCzAn/TPBi/LiF/Al. The CzAnCz device has turn on voltage of 4.0V, a maximum luminance of 1510 cd/m2, a maximum EQE of 1.30%, and a current efficiency of 1.19 cd/A. AnCz device has a turn on voltage of 3.6V, a maximum luminance of 2882 cd/m2, a maximum EQEof 1.50%, a current efficiency of 2.02 cd/A, an AnCzAn turn on voltage of 4.0V, and a maximumluminance of 1340 cd/m2. The EQE was 0.64% and the current efficiency was 1.11 cd/A.