Journal article
Direct van der Waals epitaxy of crack-free AlN thin film on epitaxial WS2
Van der Waals epitaxy (vdWE) has drawn continuous attention, as it is unlimited by lattice-mismatch between epitaxial layers and substrates. Previous reports on the vdWE of IIInitride thin film were mainly based on two-dimensional (2D) materials by plasma pretreatment or pre-doping of other hexagonal materials.
However, it is still a huge challenge for single-crystalline thin film on 2D materials without any other extra treatment or interlayer. Here, we grew highquality single-crystalline AlN thin film on sapphire substrate with an intrinsic W2 overlayer (W2/sapphire) by metal-organic chemical vapor deposition, which had surface roughness and defect density similar to that grown on conventional sapphire substrates.
Moreover, an AlGaNbased deep ultraviolet light emitting diode structure on W2/sapphire was demonstrated. The electroluminescence (EL) performance exhibited strong emissions with a single peak at 283 nm. The wavelength of the single peak only showed a faint peak-position shift with increasing current to 80 mA, which further indicated the high quality and low stress of the AlN thin film.
This work provides a promising solution for further deep-ultraviolet (DUV) light emitting electrodes (LEDs) development on 2D materials, as well as other unconventional substrates.
Language: | English |
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Publisher: | MDPI |
Year: | 2018 |
Pages: | 2464 |
ISSN: | 19961944 |
Types: | Journal article |
DOI: | 10.3390/ma11122464 |
ORCIDs: | Ou, Haiyan |