Huang Rui, Xu Shuigang, Guo Yanqing, Guo Wenhao, Wang Xiang, Song Chao, Song Jie, Wang Lin, Ho Kin Ming, Wang Ning
Department of Physics and Electronic Engineering, Hanshan Normal University, Chaozhou, Guangdong 521041, China.
Opt Express. 2013 Mar 11;21(5):5891-6. doi: 10.1364/OE.21.005891.
We report a remarkable improvement of photoluminescence from ZnO-core/a-SiN(x):H-shell nanorod arrays by modulating the bandgap of a-SiN(x):H shell. The a-SiN(x):H shell with a large bandgap can significantly enhance UV emission by more than 8 times compared with the uncoated ZnO nanorods. Moreover, it is found that the deep-level defect emission can be almost completely suppressed for all the core-shell nanostructures, which is independent of the bandgaps of a-SiN(x):H shells. Combining with the analysis of infrared absorption spectrum and luminescence characteristics of NH(x)-plasma treated ZnO nanorods, the improved photoluminescence is attributed to the decrease of nonradiative recombination probability and the reduction of surface band bending of ZnO cores due to the H and N passivation and the screening effect from the a-SiN(x):H shells. Our findings open up new possibilities for fabricating stable and efficient UV-only emitting devices.
我们报道了通过调节a-SiN(x):H壳层的带隙，ZnO核/a-SiN(x):H壳层纳米棒阵列的光致发光有显著改善。与未包覆的ZnO纳米棒相比，具有大带隙的a-SiN(x):H壳层可将紫外发射显著增强8倍以上。此外，发现对于所有核壳纳米结构，深能级缺陷发射几乎可以完全被抑制，这与a-SiN(x):H壳层的带隙无关。结合对NH(x)等离子体处理的ZnO纳米棒的红外吸收光谱和发光特性的分析，光致发光的改善归因于非辐射复合概率的降低以及由于H和N钝化以及a-SiN(x):H壳层的屏蔽效应导致的ZnO核表面能带弯曲的减小。我们的发现为制造稳定且高效的仅发射紫外光的器件开辟了新的可能性。
