Three kinds of carbonized polymer dots(CPDs) synthesized via a one-pot process from ophenylenediamine(OPD), m-phenylenediamine(MPD) and p-phenylenediamine(PPD) exhibit excitationwavelength independent yellow, green an...Three kinds of carbonized polymer dots(CPDs) synthesized via a one-pot process from ophenylenediamine(OPD), m-phenylenediamine(MPD) and p-phenylenediamine(PPD) exhibit excitationwavelength independent yellow, green and red emissions, respectively. In sharp contrast, two kinds of CPDs prepared via a hydrothermal process from citric acid(CA) and diethylenetriamine(DETA) exhibit obvious excitation-wavelength dependent emissions. Through the characterization and comparison of the two types of CPDs, it is concretely revealed that the polymer structure types during the formation of CPDs can effectively control the fluorescence excitation-wavelength independence/dependence. The homogeneous polymer structures contained in CPDs contribute to excitation-wavelength independence, whereas random copolymer structures contribute to excitation-wavelength dependence. These studies are of great significance for further understanding the polymer structures and designing unique optical properties of CPDs.展开更多
In this paper, highly efficient phosphorescent organic lighting emitting diodes （PhOELDs） with low efficiency roll-off are demonstrated by using a unilateral homogenous device structure with wide band-gap material 4...In this paper, highly efficient phosphorescent organic lighting emitting diodes （PhOELDs） with low efficiency roll-off are demonstrated by using a unilateral homogenous device structure with wide band-gap material 4, 4＇, 4＂-tri（N-carbazolyl）-triphenylamine （TCTA） as hole transporting layer and emitting layer （EML）. The opti- mized blue device exhibits a high power efficiency of 40 lm/W, external quantum efficiency of 19.2% and current efficiency of 37.7cd/A. More importantly, the device exhibits a low efficiency roll-off at 1000 cd/m^2. In addition, the white homogenous PhOLEDs only exhibits the efficiency roll-off 5.6% and 17.5%, corresponding to the brightness of 1000 and 5000cd/m^2 respectively. These interesting results demonstrate that the simple unilateral homogenous device structure is a promising way to enhance the device efficiency and reduce the efficiency roll-off.展开更多
基金the Priority Academic Program Development of Jiangsu Higher Education Institutions (No. 1107047002)the Key Research and Development Plan (Modern Agriculture) of Jiangsu Province (No. BE2018385)Innovation Platform Project supported by Jiangsu Province (No. 6907041203)。
文摘Three kinds of carbonized polymer dots(CPDs) synthesized via a one-pot process from ophenylenediamine(OPD), m-phenylenediamine(MPD) and p-phenylenediamine(PPD) exhibit excitationwavelength independent yellow, green and red emissions, respectively. In sharp contrast, two kinds of CPDs prepared via a hydrothermal process from citric acid(CA) and diethylenetriamine(DETA) exhibit obvious excitation-wavelength dependent emissions. Through the characterization and comparison of the two types of CPDs, it is concretely revealed that the polymer structure types during the formation of CPDs can effectively control the fluorescence excitation-wavelength independence/dependence. The homogeneous polymer structures contained in CPDs contribute to excitation-wavelength independence, whereas random copolymer structures contribute to excitation-wavelength dependence. These studies are of great significance for further understanding the polymer structures and designing unique optical properties of CPDs.
基金Acknowledgements This research work was supported by the National Natural Science Foundation of China （Grant Nos. 21161160442 and 51203056）, the National Basic Research Program of China （973 Program） （No. 2013CB922104）, Wuhan Science and Technology Bureau （No. 01010621227） and the Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry.
文摘In this paper, highly efficient phosphorescent organic lighting emitting diodes （PhOELDs） with low efficiency roll-off are demonstrated by using a unilateral homogenous device structure with wide band-gap material 4, 4＇, 4＂-tri（N-carbazolyl）-triphenylamine （TCTA） as hole transporting layer and emitting layer （EML）. The opti- mized blue device exhibits a high power efficiency of 40 lm/W, external quantum efficiency of 19.2% and current efficiency of 37.7cd/A. More importantly, the device exhibits a low efficiency roll-off at 1000 cd/m^2. In addition, the white homogenous PhOLEDs only exhibits the efficiency roll-off 5.6% and 17.5%, corresponding to the brightness of 1000 and 5000cd/m^2 respectively. These interesting results demonstrate that the simple unilateral homogenous device structure is a promising way to enhance the device efficiency and reduce the efficiency roll-off.
