Open AccessLuminescence enhancement of ZnO-core/a-SiN_x:H-shell nanorod arrays
Author(s) -
Rui Huang,
Sean Xin Xu,
Yanqing Guo,
Wenhao Guo,
Xiang Wang,
Chao Song,
Jie Song,
Lin Wang,
K. M. Ho,
Ning Wang
Publication year - 2013
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.005891
Subject(s) - nanorod , photoluminescence , materials science , passivation , luminescence , optoelectronics , band gap , nanostructure , shell (structure) , core (optical fiber) , spontaneous emission , infrared , absorption (acoustics) , nanotechnology , optics , composite material , physics , layer (electronics) , laser
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.