کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1616490 | 1516380 | 2012 | 5 صفحه PDF | دانلود رایگان |
MgZnO/MgO strained multiple-quantum-wells (S-MQWs) with different structures are grown by pulsed laser deposition. The S-MQW films are composed of closely arranged, vertically oriented nanocolumns. Z-contrast scanning transmission electron microscopy observations and line-scan compositional analysis reveal that the nanocolumns are compositionally modulated along their length and have a MQW structure. A coherent epitaxial relationship with a sharp interface is established between MgZnO and MgO layers with large lattice mismatch. It is worth noting that the MgZnO layer undergoes a structural transition from hexagonal to cubic phase with its thickness decreasing. The calculations reveal that a large in-plane compressive stress dominates such an interesting phase transition process, stabilizes the low Mg-content MgZnO alloy in the anomalous cubic phase, and also leads to a broadening of the band gap. As a result, the wavelength-tunable deep-ultraviolet emission in the range of 261–314 nm is obtained from these S-MQW nanocolumnar films. The 261 nm is known to be the shortest emission wavelength ever reported for MgZnO material.
► MgZnO/MgO strained multiple-quantum-wells nanocolumnar films are achieved.
► A epitaxial relationship with high-quality interface is established between MgZnO and MgO layers with large lattice mismatch.
► Stress-induced structural transition of MgZnO layers is observed.
► The wavelength-tunable deep-ultraviolet emission is obtained, and the 261 nm is known to be the shortest emission wavelength ever reported for MgZnO material.
Journal: Journal of Alloys and Compounds - Volume 513, 5 February 2012, Pages 399–403