In this study, Mg_xZn_1-xO thin films, which can be applied not only to active layers of light-emitting devices (LEDs), such as UV-LEDs, but also to solar cells, high mobility field-effect transistors, and power semiconductor devices, are fabricated using the sol-gel method. ZnO and Mg_0.3Zn_0.7O solution synthesized by the sol-gel method and the thin film were grown by spin coating on a Si (100) substrate and sapphire substrate. The solutions are synthesized by dissolving precursor materials in 2-methoxyethanol (2-ME) solvent, and then monoethanolamine (MEA) was added to the mixed solution as a sol stabilizer. Zinc acetate dihydrate is used as a ZnO precursor, while Mg nitrate hexahydrate and Mg acetate tetrahydrate are used as an MgO precursor. Then, the optical and structural characteristics of the fabricated thin films are compared. The molar concentration of the Zn precursor in the solvent is fixed at 0.3 M, and the amount of the Mg precursor is 30% of Mg²⁺/Zn²⁺. The optical characteristics are measured using an UV-vis spectrophotometer, and the transmittance of each wavelength is measured. Structural characteristics are measured using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Composition analyses are performed using energy dispersive X-ray spectroscopy (EDS). The Mg_0.3Zn_0.7O thin film was well formed at the ratio of the Mg precursor added regardless of the type of Mg precursor, and the c-axis of the thin film was decreased, while the band gap was increased to 3.56 eV.

We report the characteristics of thin-film transistor (TFT) to make the bi-channel structure with stacked Mg0.1ZnO0.9O (Mg= 10 at.%) and ZnO. The ZnO and Mg0.1Zn0.9O thin films were deposited by radio frequency (RF) co-sputter system onto the thermally oxidized silicon substrate. A total thickness of active layer was 50 nm. Firstly, the ZnO thin films were deposited to control the thickness from 5 nmto 30 nm. Sequentially, the Mg0.1Zn0.9O thin films were deposited to change from 45 nm to 20 nm. Thebi-layer TFT shows more improved properties than the single layer TFT. The field effect mobility and sub threshold slope for Mg0.1Zn0.9O/ZnO-TFT are 7.40 cm2V-1s-1 and 0.24 V/decade at the ZnO thickness of 10 nm, respectively.

Concern for the TOS (Transparent Oxide Semiconductor) is increasing with the recent increase in interest for flexible device. Especially MgZnO has attracted a lot of attention. MgxZn1-xO, which ZnO-based wideband-gap alloys is tuneable the band-gap ranges from 3.36 eV to 7.8 eV. In particular, the flexible substrate, the crystal structure of the amorphous as well as the surface morphology is not good. So research of MgZnO thin films growth on flexible substrate is essential. Therefore, in this study, we studied on the effects of the oxygen partial pressure on the structural and crystalline of Mg0.1Zn0.9O thin films. MgZnO thin films were deposited on PES substrate by using pulsed laser deposition. We used XRD and AFM in order to observe the structural characteristics of MgZnO thin films. UV-visible spectrophotometer was used to get the band gap and transmittance. Crystallization was done at a low oxygen partial pressure. The crystallinity of MgZnO thin films with increasing temperature was improved, Grain size and RMS of the films were increased. MgZnO thin films showed high transmittance over 80% in the visible region.

The effect of co-sputtering condition on the structural properties of Mg_xZn_1-xO thin films grown by RF magnetron co-sputtering system was investigated for manufacturing UV LED. Mg_xZn_1-xO thin films were grown with ZnO and MgO target varying RF power. Structural properties were investigated by X-ray diffraction (XRD) and Energy dispersive spectroscopy (EDS). The Mg_xZn_1-xO thin films have sufficient crystallinity on the high ZnO power. The EDS analyzed showed that the Mg content in the Mg_xZn_1-xO films decreased from 3.99 to 24.27 at.% as the RF power of ZnO target increased. The Mg content in the Mg_xZn_1-xO films could be controlled by co-sputtering power.

The effect of co-sputtering condition on the structural properties of MgxZn1-xO thin films grown by RF magnetron co-sputtering system was investigated for manufacturing ZnO/MgZnO structure LED. MgxZn1-xO thin films were grown with ZnO and MgO target varying RF power. Structural properties were investigated by X-ray diffraction (XRD) and Energy dispersive spectroscopy (EDS). The ZnO thin films have sufficient crystallinity on the high RF power. As RF power of ZnO target increased, the contents of MgO in the MgxZn1-xO film decreased. LED was manufactured using ZnO/MgZnO multi-layer on p-GaN/Al2O3 substrate. Threshold voltage of multi-layer LED was appeared at 8 V, and it was luminesced at wave length of 550 nm.

In this work, we study on the effects of the oxygen pressure on the structural and crystalline of MgZnO thin films. MgZnO thin films were deposited on p-Si (111) substrates by using pulsed laser deposition. The X-ray diffraction analysis and energy dispersive X-ray results revealed that as the oxygen pressure increased and Mg content in the MgZnO films decreased. Also Crystal structure was changed from cubic rock salt to hexagonal wurtzite. Alpha step and atomic force microscopy results showed that the thickness of the films are about 100 nm, and it has been found that the MgZnO (002) preferred orientation were deposited with increasing the oxygen pressure. Therefore, the effect of the preferred orientation, the crystallization grew in the form of the columnar; Grain size and RMS of the films were increased with increasing oxygen pressure.