MgZnO/MgO strained multiple-quantum-well nanocolumnar films: Stress-induced structural transition and deep ultraviolet emission

Temperature dependence of Raman scattering in β-(AlGa)2O3 thin films

“…Figure 8 displays the ratios of A and B for A g (3) and A g (10) phonon modes of Ga 2 O 3 and (AlGa) 2 O 3 films. It is obvious that the ratios of A and B are much larger than 1.0, indicating that the decay into two phonons is the prevailing process while the contribution from the four phonon processes is minor in the anharmonic coupling of A g (3) and A g (10) phonon modes. This result has a well agreement with the report on Ga 2 O 3 bulk, 18 which further indicates the reliability of our results estimated by theoretical fitting.…”

“…[1][2][3][4] As a wide variable bandgap semiconductor, ternary (AlGa) 2 O 3 is a promising candidate for deep ultraviolet optoelectronic device applications because (AlGa) 2 O 3 has an advantage of large tunable bandgaps from 4.8 eV (Ga 2 O 3 ) to 8.6 eV (Al 2 O 3 ) at room temperature. 5,6 In order to realize (AlGa) 2 O 3 application in deep ultraviolet optoelectronic devices, great efforts have made remarkable progress for growing this alloy.…”

Controlled response wavelength shifting in ultraviolet photodetectors based on double-layer films

“…Besides, the double-layer films, especially the nanoscale MgZnO/MgO prepared by the Xu et al, often display many interesting properties, such as broadening band gap and interesting phase transition. [24][25][26] Therefore, the double-layer films structure is a suitable choice for realizing controlled response wavelength shifting UV PDs, which will open up opportunities towards tuning the response wavelength by the film structure. In this communication, we utilize the concept of constructing the response wavelength tunable UV PDs by radio frequency (RF) magnetron sputtering method, which is based on two comparable double-layer films structures.…”

Anisotropic strained cubic MgZnO/MgO multiple-quantum-well nanorods: Growths and optical properties

“…Recently, it has been reported that RS phase Mg x Zn 1Àx O for x < 30% could be realized when the low Mg content MgZnO thin layers were under the control of a high lattice mismatch strain field. 16 Although large strain field in hetero-epilayers usually generates a large number of crystal defects like dislocations, twins, and stacking faults, it has been reported that strain accommodation in low-dimensional GaN nanostructures like nanowires and nanorods could help people growing highly strained structures with relative low defect densities, which was not feasible in strained planar QW structures and heteroepitaxial thin films. 17,18 By combining both energy band engineering and strain engineering, low-dimensional structures specially designed for DUV optoelectronic applications could be realized.…”

“…Details of the growth procedure have been described in our previous report. 16 Briefly, the growths were performed with an oxygen (5 N) partial pressure of 20 Pa and the substrate temperature of 400 C. Mg 0.21 Zn 0.79 O/MgO MQW structures consisting 16 periods were grown on Al 2 O 3 ð10 10Þ substrates. In order to modify the in plane stress, three samples have been grown with the thicknesses of MgZnO wells/MgO barriers being 10 nm/3 nm (sample 1), 5 nm/6 nm (sample 2), and 3 nm/7.2 nm (sample 3), respectively.…”