Hussain Ijaz, Bano Nargis, Hussain Sajjad, Soomro Yousuf, Nur Omer, Willander Magnus
Department of Science and Technology, Campus Norrköping, Linköping University, SE-60174 Norrköping, Sweden.
Materials (Basel). 2011 Jul 8;4(7):1260-1270. doi: 10.3390/ma4071260.
In this study, the low temperature aqueous chemical growth (ACG) method was employed to synthesized ZnO nanorods to process-organic hybrid white light emitting diodes (LEDs) on glass substrate. Electroluminescence spectra of the hybrid white LEDs demonstrate the combination of emission bands arising from radiative recombination of the organic and ZnO nanorods (NRs). Depth resolved luminescence was used for probing the nature and spatial distribution of radiative defects, especially to study the re-absorption of ultraviolet (UV) in this hybrid white LEDs structure. At room temperature the cathodoluminescence (CL) spectra intensity of the deep band emission (DBE) is increased with the increase of the electron beam penetration depth due to the increase of defect concentration at the ZnO NRs/Polyfluorene (PFO) interface and probably due to internal absorption of the UV. A strong dependency between the intensity ratio of the UV to the DBE bands and the spatial distribution of the radiative defects in ZnO NRs has been found. The comparison of the CL spectra from the PFO and the ZnO NRs demonstrate that PFO has a very weak violet-blue emission band, which confirms that most of the white emission components originate from the ZnO NRs.
在本研究中，采用低温水相化学生长（ACG）法在玻璃基板上合成氧化锌纳米棒，以制备有机-无机杂化白光发光二极管（LED）。杂化白光LED的电致发光光谱表明，有机材料与氧化锌纳米棒（NRs）辐射复合产生的发射带相互叠加。深度分辨发光用于探测辐射缺陷的性质和空间分布，特别是研究这种杂化白光LED结构中紫外线（UV）的再吸收情况。在室温下，由于氧化锌NRs/聚芴（PFO）界面处缺陷浓度的增加以及可能的紫外线内部吸收，深带发射（DBE）的阴极发光（CL）光谱强度随着电子束穿透深度的增加而增强。已发现紫外线与DBE带的强度比和氧化锌NRs中辐射缺陷的空间分布之间存在很强的相关性。来自PFO和氧化锌NRs的CL光谱比较表明，PFO具有非常弱的紫蓝色发射带，这证实了大部分白色发射成分源自氧化锌NRs。
