Novel beryllium complex as the non-doped emitter for highly efficient deep-blue organic light-emitting diode

Efficient blue organic light-emitting diodes have been developed based on one novel fluorescent beryllium complex bis(2-(2-hydroxyphenyl)-4-methyl-pyridine)beryllium (Be(4-mpp)2). The simple double-layer device based on Be(4-mpp)2 as the EML as well as the ETL not only shows pure and stable blue emission with the CIE coordinates of (0.14, 0.09), but also presents very high EL efficiency in terms of both the peak values (5.4% for EQE and 4.2 lm W−1 for PE) and the EQE value remaining ⩾4.0% in very wide brightness range (10–10,000 cd m−2) that indicates very good operational stability. They are the highest EL efficiencies ever reported for such saturated and stable OLED (CIE: x < 0.15, y < 0.10) to the best of our knowledge.

Graphical abstractEfficient blue organic light-emitting diodes have been developed based on one novel fluorescent beryllium complex bis(2-(2-hydroxyphenyl)-4-methyl-pyridine)beryllium (Be(4-mpp)2). The simple double-layer device based on Be(4-mpp)2 as the EML as well as the ETL not only shows pure and stable blue emission with the CIE coordinates of (0.14, 0.09), but also presents very high EL efficiency in terms of both the peak values (5.4% for EQE and 4.2 lm W−1 for PE) and the EQE value remaining ⩾4.0% in very wide the brightness range (10–10,000 cd m−2) that indicates very good operational stability. These values mentioned above are the highest EL efficiencies ever reported for such saturated deep-blue OLED to the best of our knowledge.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A novel fluorescent blue-emission complex Be(4-mpp)2 was developed. ► Be(4-mpp)2-based device exhibited deep-blue EL with the stable CIE (0.14, 0.09). ► The non-doped blue OLED showed very high EL efficiency of 5.4% and 4.2 lm W−1.