Growth of new transparent conducting materials, gallium oxide single crystals, and their carrier doping

本研究建立了可广泛借鉴的技术基础知识和研究成果数据库，采用提拉法（Cz）、μ-下拉法（μ-PD）和浮区法（Fz）三种生长技术，生长了（Ga_<1-x>W_x）_2O_3、（Ga_ Mo_x）_2O_3、<1-x>（Ga_ Ge<1-x>_x）_2O_3、（Ga_ Hf<1-x>_x）_2O_3、（Ga_Zr_x）_2O_3<1-x>等多种掺杂Ga_2 O_3单晶，并对其电学和光学性能进行了研究。用热处理方法使生长的Ga_2O_3晶体缺氧，获得了n型半导体Ga_2O_3单晶。主要研究成果如下：1.本文建立了一种用提拉法生长掺杂Ga_2O_3单晶的工艺。在电学和光学性质方面，生长出的单晶分别具有明显的n型半导性和蓝色发光特性.建立了μ-PD法生长掺杂Ga_2O_3单晶的工艺。在电学和光学性质方面，生长出的单晶分别具有明显的n型半导性和蓝色发光特性.建立了Fz法生长掺杂Ga_2O_3单晶的工艺。在电学和光学性质方面，生长出的单晶分别具有明显的n型半导性和蓝色发光特性.对于Cz法、μ-PD法和Fz法生长的晶体，通过优化混合气体（氧和氮）的分压和热处理温度，使晶体具有适当的氧缺陷，从而改善了晶体的n型半导体性能。

In this study, we established all technologies and made database all research results, which can be referred widely as basic technological knowledge.By three growth technologies such as Czochralski (Cz), μ-Pulling Down (μ-PD) and Floating Zone (Fz) methods, various doped Ga_2O_3 single crystals such as (Ga_<1-x>W_x)_2O_3, (Ga_<1-x>Mo_x)_2O_3, (Ga_<1-x>Ge_x)_2O_3, (Ga_<1-x>Hf_x)_2O_3, (Ga_<1-x>Zr_x)_2O_3 were grown and their electrical and optical properties were investigated. Also, by using thermal treatment as a tool to make a oxygen deficiency for the grown crystals, Ga_2O_3 single crystals of n-type semiconducting was realized. We summarize the research results as follows:1. We established a technology to grow doped Ga_2O_3 single crystals by Cz method. For electrical and optical properties of the grown single crystals, the features of n-type semiconducting and blue luminescence, respectively, were clearly revealed.2. We established a technology to grow doped Ga_2O_3 single crystals by μ-PD method. For electrical and optical properties of the grown single crystals, the features of n-type semiconducting and blue luminescence, respectively, were clearly revealed.3. We established a technology to grow doped Ga_2O_3 single crystals by Fz method. For electrical and optical properties of the grown single crystals, the features of n-type semiconducting and blue luminescence, respectively, were clearly revealed.4. For the grown crystals by Cz, μ-PD, and Fz methods, the n-type semiconducting property was improved by optimizing partial pressure of mixture gas (oxygen and nitrogen) and thermal treatment temperature so that the crystals are of proper oxygen-deficiency.