标题：Solid-liquid interface optimization and properties of ultra-wide bandgap beta-Ga2O3 grown by Czochralski and EFG methods
作者：Mu, Wenxiang; Jia, Zhitai; Yin, Yanru; Fu, Bo; Zhang, Jin; Zhang, Jian; Tao, Xutang
作者机构：[Jia, Zhitai; Tao, Xutang] Shandong Univ, State Key Lab Crystal Mat, Jinan 250100, Shandong, Peoples R China.; Shandong Univ, Key Lab Funct Crystal 更多
通讯作者：Jia, ZT;Tao, XT;Jia, Zhitai
通讯作者地址：[Jia, ZT; Tao, XT]Shandong Univ, State Key Lab Crystal Mat, Jinan 250100, Shandong, Peoples R China.
摘要：Herein, the solid-liquid interface and bulk crystal growth habit of beta-Ga2O3 were studied during the Czochralski and the modified edge-defined film-fed growth (EFG) methods, respectively. The technical characteristics and process optimizations of the two methods were systematically compared and explored during the crystal growth of beta-Ga2O3. In the Czochralski method, the phenomenon of spiral growth was explained based on a concave solid-liquid interface and heat transfer at high temperatures. To overcome the problem of spiral growth, a square Ir die was designed and used for the growth of beta-Ga2O3 in the EFG method, and high quality beta-Ga2O3 single crystals were obtained with a flat interface. The full-width at half-maximum (FWHM) of the X-ray rocking curve on the (100)-faced beta-Ga2O3 grown by the EFG method was only 35.6 arcsec, indicating high crystalline quality. The carrier source of the unintentionally doped beta-Ga2O3 was determined via impurity elemental analysis. A relationship between the carrier concentrations and mid-IR transmission was established. Furthermore, the PL and Raman spectra of the as-grown and annealed crystals were obtained to reveal the energy structure and stress in the crystal.