The 67th JSAP Spring Meeting 2020

Presentation information

Oral presentation

15 Crystal Engineering » 15.2 II-VI and related compounds

[13a-D215-1~7] 15.2 II-VI and related compounds

Fri. Mar 13, 2020 9:00 AM - 10:45 AM D215 (11-215)

Tamotsu Okamoto(Natl. Inst. of Tech., Kisarazu Col.)

9:15 AM - 9:30 AM

[13a-D215-2] Improved properties of low-resistive Al-doped ZnCdO thin films by MBE.

〇(D)HyoChang Jang1, Katsuhiko Saito1, Qixin Guo1, Tooru Tanaka1 (1.Saga Univ.)

Keywords:ZnCdO, Molecular beam epictaxy, Thin film

Recently, a II-VI semiconductor material based on CdO (band gap energy of 2.3 eV) is expected to realize low resistive thin films at a low carrier concentration which can suppress a free carrier absorption and a plasma reflection, leading to a high transparency in long wavelength up to infrared region. Although the band gap of CdO is small for a transparent conductive oxide (TCO) application, it can be expanded by alloying with ZnO which has a band gap of ~3.3 eV. However, because CdO has a rocksalt (RS) structure (a=4.70 Å), whereas ZnO has a wurtzite (WZ) structure (a=3.25 Å, c=5.21 Å), the crystal structure of Zn1-xCdxO (ZnCdO) is expected to change at a certain Cd composition.
In the previous study, we have grown Al-doped ZnCdO thin films on MgO (100) substrates by radical-source molecular beam epitaxy (MBE) under the oxygen flow rate of 0.3 sccm, and found that the phase transition takes place at the Cd composition x~0.69 and the largest band gap is ~3.23 eV in RS structure. The oxygen flow rate affects to the growth properties of ZnCdO. Here, we have grown Al-doped ZnCdO thin films on MgO (100) substrate under the oxygen flow rate of 1.0 sccm and found improved optical and electrical properties by increasing oxygen flow rate.