Structural and electronic properties of ZnMgO/ZnO quantum wells

Temperature dependence of Zn1−xMgxO films grown on c-plane sapphire by metal organic vapor phase epitaxy

“…One can change the bandgap of a semiconductor by alloying it with a material of a different bandgap to form a ternary compound, while paying attention to the lattice parameter mismatch, which has to be reduced as much as possible. To increase the fundamental bandgap energy of ZnO film from 3.36 to 4.15 eV, a large number of reports [1][2][3][4][5][6][7] have alloyed ZnO with different concentrations of MgO to form the ternary compound Zn 1 À x Mg x O, which is considered as a suitable barrier layer in the ZnO/Zn 1 À x Mg x O quantum well structures [8][9][10][11].…”

“…Using MOVPE, different combinations of precursors were chosen to fabricate this alloy. These are: (i) diethylzinc (DEZn) with O 2 and biscyclopentadienyl magnesium (CP 2 Mg) [3,[4][5][6][7][8][9][10][11][12][13][14][15][16][17], (ii) DEZn with O 2 or N 2 O and bismethylcyclopentadienyl magnesium ((MCP) 2 Mg) [5,8,16], and (iii) DEZn with N 2 O and ethylbiscyclopentadienyl magnesium (EtCP 2 Mg) [7]. The Mg composition measured in the solid solution was up to 0.38 [1].…”

Characterization of microstructure and defects in epitaxial ZnO films on Al2O3 substrates by transmission electron microscopy

“…In this case, a strong built-in electrostatic field appears in the ZnO film as a result of spontaneous and piezoelectric polarizations caused by the noncentrosymmetric nature of wurtzite crystal structure. The polarization-induced electric field results in the quantum confined Stark effect (QCSE) [2,3], which acts as a negative factor on a performance of the light-emitting devices [4][5][6]. One of the direct ways to eliminate the effect of polarization fields on devices is growing the films with nonpolar directions.…”

Growth kinetics and properties of ZnO/ZnMgO hetero‐ structures grown by radical‐source molecular beam epitaxy

“…After only a few nm ZnO growth, an intense RHEED specular spot appeared and a (3x3) reconstruction pattern sometimes evolved. Some structures included a 50-500-nm-thick ZnMgO layer grown on top of a high quality ZnO layer at r = 0.06-0.15 nm s -1 and T S = 310-400 °C recently shown to be optimum [9,10]. The grown heteroepitaxial layers were ex-situ investigated by using atomic force microscopy (AFM), scanning electron microscopy, high-resolution x-ray diffractometry (HR XRD), and photoluminescence (PL) spectroscopy.…”