Substrate engineering of LaAlO3 for non-polar ZnO growth

Room-temperature electrically pumped near-infrared random lasing from high-quality m-plane ZnO-based metal-insulator-semiconductor devices

“…Figure 2 b,c and the inset of Figure 2 a show the selected area electron diffraction (SAED) patterns of the sapphire substrate, the ZnO thin film, and the interface region, respectively. The growth direction of the ZnO thin film is along [ 10 ] as presented in Figure 2 b, in full agreement with the XRD result. The orientation relationships between the ZnO thin film and the sapphire substrate can be manifested as follows: ZnO [0001]//sapphire [1–210] and ZnO (−12-10)//sapphire (0006), which are demonstrated in the inset of Figure 2 a.…”

“…Figure 1 a shows the XRD spectra of the ZnO thin films deposited on the m-plane sapphire substrates, in which the ZnO (10–10) peak is observed besides the sapphire (30–30) peak, clearly indicating that the ZnO thin films are predominantly grown along the [ 10 ] direction. The φ scans of the sapphire (10–12) peak and ZnO (10–13) peak are presented in Figure 1 b.…”

“…Therefore, semi-polar and nonpolar structures are proposed to diminish or even eliminate the polarization effects, and the nonpolar m-plane is one of the common structures [ 6 ]. Unfortunately, due to the coexistence of minor domains with <0001>, <11-22>, or <10-13 > growth directions in m-plane ZnO thin films [ 7 - 9 ], it is difficult to deposit high-quality and smooth m-plane ZnO thin films by several normal growth techniques, such as molecular beam epitaxy [ 7 , 8 ], metalorganic chemical vapor deposition [ 9 ], and pulsed laser deposition [ 10 ]. In addition, with different growth conditions, various striped features are usually presented on the surface of m-plane ZnO thin films deposited on foreign substrates [ 11 , 12 ].…”

The Effect of Tensile Strain on Optical Anisotropy and Exciton of <inline-formula> <tex-math notation="TeX">$m$</tex-math></inline-formula>-Plane ZnO

“…Fig. 1(a) shows the -2 scan of ZnO films grown on (112)LAO substrates, showing (1100), (2200) peaks of ZnO and (112) peak of LAO, thus confirming that the m-plane ZnO was successfully grown on the (112)LAO substrate [10]. Based on the (2200) peak at 66.55 , the corresponding strain " yy along out of plane direction can be evaluated as À0.21%.…”

“…Fig. 1(b) shows the in-plane ' scan of the ZnO film, indicating two-fold symmetry, which suggests the epitaxial growth of m-plane ZnO films on (112)LAO [10]. More detailed materials characterizations for epitaxial m-plane ZnO film on (112)LAO can be found elsewhere [8].…”