据美国C&EN周刊2011年4月18日报道，加拿大多伦多大学同时又是云南大学物理系的LU Zheng-hong教授领导的研究小组，成功的研制出一种有机发光二极管（OLEDs）氯化电极材料，在传统OLED(有机发光二极管)的电极材料上涂上一层氯原子涂层，不但可提高OLED的发光效率，还能大幅简化生产工序，降低生产成本，将加速OLED在主流平板显示和其他发光技术上的应用。C&EN的介绍如下，但是LU教授等人的原始研究论文于2011年4月14日在Science网站公布（DOI: 10.1126/science.1202992）。

据负责该项研究的加拿大多伦多大学有关研究人员介绍，这项技术的应用极为简便，只需在现有标准工业化OLED的电极材料氧化铟锡(ITO，也称掺锡氧化铟)上增加一层一个原子厚的氯元素涂层即可。新技术不但能够提高传统OLED的电气性能，还能省去在传统OLED上大量应用的多种昂贵涂层。在氧化铟锡上涂上一层一个原子厚的氯并非难事，他们已经开发出了一种通过紫外线辅助氯化技术，可以免去使用氯气过程，从而使整个生产过程更为安全可靠。长期以来OLED都以高效闻名，但在提高亮度的情况下其效能就会出现显著的快速下降。为了对新型OLED的发光效能进行验证，研究人员将这种氯化OLED(Cl-OLED)与传统的OLED进行了对比测试。结果发现，具有氯原子涂层的OLED在提高亮度后可以避免效能下降，在发光亮度非常高的情况下，工作效率可提高一倍多。更多信息请浏览原文。

Chlorination Improves Organic Electronics

Chlorinating a common electrode material for organic light-emitting diodes (OLEDs) could make devices easier and less expensive to manufacture, researchers report (Science, DOI: 10.1126/science.1202992).

In a typical OLED, electrons move from an organic, light-emitting material to indium tin oxide. But the energy of the electrons removed from the light-emitting material is higher than the oxide can accept. Consequently, layers of other materials—for example, copper phthalocyanine—are used to bridge the gap and facilitate electron flow. The additional layers, however, add cost and complexity to manufacturing and reduce the electrical efficiency of electronic devices.

In an effort to do without those extra layers, a research group led by materials science and engineering graduate students Michael G. Helander and Zhibin Wang and professor Zhenghong Lu at the University of Toronto chlorinated the electrodes by exposing the material to o-dichlorobenzene and ultraviolet light. The treatment causes chlorine radicals from the solvent to displace oxygen and bind to indium on the electrode surface.

The resulting layer of polar In–Cl bonds increases the electrostatic potential just above the electrode’s surface. That change in potential increases the electron energy that the electrode can accept and closes the energy gap between the electrode and light-emitting materials, such as a phosphorescent iridium complex doped into 4,4´-N,N´-dicarbazole biphenyl. Electrons can then directly transfer between the light-emitting layer and the chlorinated electrode, making electronic devices easier to manufacture and more efficient to operate.

The prototype devices made by the Toronto group show a substantial improvement in operating voltages and efficiency, says Franky So, a materials science and engineering professor at the University of Florida. “This approach might lead to a paradigm shift in OLED technology.”