Chen Yungting, Shih Hanyu, Wang Chunhsiung, Hsieh Chunyi, Chen Chihwei, Chen Yangfang, Lin Taiyuan
Department of Physics, National Taiwan University, Taipei 106, Taiwan.
Opt Express. 2011 May 9;19 Suppl 3:A319-25. doi: 10.1364/OE.19.00A319.
Based on hybrid inorganic/organic n-ZnO nanorods/p-GaN thin film/poly(3-hexylthiophene)(P3HT) dual heterojunctions, the light emitting diode (LED) emits ultraviolet (UV) radiation (370 nm - 400 nm) and the whole visible light (400 nm -700 nm) at the low injection current density. Meanwhile, under the high injection current density, the UV radiation overwhelmingly dominates the room-temperature electroluminescence spectra, exponentially increases with the injection current density and possesses a narrow full width at half maximum less than 16 nm. Comparing electroluminescence with photoluminescence spectra, an enormously enhanced transition probability of the UV luminescence in the electroluminescence spectra was found. The P3HT layer plays an essential role in helping the UV emission from p-GaN material because of its hole-conductive characteristic as well as the band alignment with respect to p-GaN. With our new finding, the result shown here may pave a new route for the development of high brightness LEDs derived from hybrid inorganic/organic heterojuctions.
基于混合无机/有机n-ZnO纳米棒/p-GaN薄膜/聚（3-己基噻吩）（P3HT）双异质结，发光二极管（LED）在低注入电流密度下发射紫外线（UV）辐射（370 nm - 400 nm）和整个可见光（400 nm - 700 nm）。同时，在高注入电流密度下，UV辐射在室温电致发光光谱中占主导地位，随注入电流密度呈指数增加，并且半高宽小于16 nm。将电致发光光谱与光致发光光谱进行比较，发现电致发光光谱中UV发光的跃迁概率大幅增强。由于P3HT层的空穴传导特性以及相对于p-GaN的能带排列，它在帮助p-GaN材料发出UV光方面起着至关重要的作用。基于我们的新发现，此处所示结果可能为开发基于混合无机/有机异质结的高亮度LED开辟一条新途径。
