氧氢共掺杂金刚石大单晶的高压合成与电学性质研究

Diamond is one of the new wide band gap high temperature semiconductor materials with a collection of many excellent performances. It has broad application prospects and is an important “strategic material” for a country. However, restricted by the inefficient donor doping elements, the preparation of n-type diamond with low resistivity and high quality has become the key problem to be solved. The related research shows that oxygen (O) doping can make the diamond turn into n-type semiconductor and the co-doping of hydrogen (H) is an important way to effectively reduce the resistivity and realize the n-type characteristics of the diamond. However, there is a lack of systematic research about the high pressure synthesis and electrical properties of O-doped and O-H co-doped diamonds. Therefore, this project is performed in the FeNi system at pressure ~8.0 GPa and temperature ~2000 K conditions, for studies on the high pressure synthesis and electrical properties of O-doped and O-H co-doped diamond large single crystals. By selecting the appropriate O and H additives, adjusting the proportions of various additives and optimizing the synthesis process, ultimately, the high quality O-doped and O-H co-doped functional diamond large single crystals will be synthesized. The content and existence forms of O and H in diamond, especially the influencing mechanism and rule of O/H contents and proportions on the functional properties of diamond will be study. This project is expected to open up new avenues for the preparation of n-type diamond and further accelerate the application of diamond-based electronic devices in industry.

金刚石是集诸多优异性能于一体的新型宽禁带高温半导体材料，应用前景十分广阔，是一个国家重要的“战略物资”。受限于有效施主掺杂元素的制约，低电阻高质量n型金刚石的制备成为亟需解决的关键问题。相关研究表明氧是能够实现金刚石n型掺杂的元素，而氢元素的共掺杂是有效降低金刚石电阻率，实现n型特征的重要途径。但高压下氧掺杂和氧氢共掺杂金刚石的研究相对欠缺，相关电学性能未有系统报道。基于此，本项目提出在~8.0 GPa，2000 K的高温高压条件下铁镍体系中开展氧掺杂和氧氢共掺杂金刚石大单晶的合成和电学性质研究。通过优选氧氢添加剂、优化合成工艺、调节氧和氢的掺杂比例，合成优质氧掺杂、氧氢共掺杂功能金刚石大单晶，探究氧、氢杂质的分布规律、掺杂机理，揭示氧、氢掺杂量和掺杂比例对金刚石电学性质的影响机制和调制规律。该项目的开展有望为制备n型金刚石开辟新的途径，进而加快金刚石基电子器件在工业中的应用。

金刚石是集诸多优异性能于一体的新型宽禁带高温半导体材料，应用前景十分广阔，是一个国家重要的“战略物资”。受限于有效施主掺杂元素的制约，低电阻高质量n型金刚石的制备成为亟需解决的关键问题，寻找有效施主元素提高金刚石晶体的电学性质十分必要。基于此，项目组围绕高压下金刚石大单晶的生长和电学性质研究，从高压合成组装腔体中温度场和对流场的模拟，到氧、硅、硼等系列元素掺杂金刚石的合成研究，再到大尺寸金刚石单晶的电学性质研究展开工作。首先，通过理论模拟为高质量金刚石大单晶生长组装的优化设计和实验参数的设定提供理论依据。然后，开展了氧、氢、硼、氮、硅等元素的单一或协同掺杂系列金刚石大单晶的合成研究，并在此基础上，利用高温高压退火技术制备了NE8色心；这些元素掺杂系列金刚石大单晶的生长和色心相关的研究为金刚石的应用提供实验技术支持。最后，对氧、硼协同掺杂系列金刚石进行了电学性质方面的研究，晶体的霍尔测试结果呈现n型电学性质，相关文章正在整理中。目前，相关工作已发表了SCI论文14篇，中文核心期刊1篇，其中包括在本领域专业期刊Crystal Growth & Design（2篇），Diamond & Related Materials（1篇），CrystEngComm（2篇）和中国科技期刊卓越行动计划期刊Chinese Physics B（2篇）等上发表相关研究成果，并作会议邀请报告一次。