Synthesis Of B-H Co-Doped Diamond Single Crystals In Differentmetal Solvent Systems

Diamond is a kind of super hard functional material with excellent properties,which is widely used in many fields.It has strong acid and alkali resistance,high transparency and other characteristics,and has the largest Mohs hardness and ultra-high thermal conductivity in nature.At present,we can’t find a material comparable to diamond.Pure diamond is not only a special functional material,but also known as jewelry.And diamond can be made into semiconductor materials by doping some specific elements.Diamond is considered as a semiconductor material with high potential because of its high frequency,high power,high heat resistance,high thermal conductivity and high carrier mobility.Boron is usually added as acceptor impurity to make semiconductor diamond,which shows the properties of p-type semiconductor.However,with the increase of boron content,the crystal quality decreases and many defects appear,and the conductivity does not increase linearly with the increase of boron content.Therefore,the preparation of boron doped diamond with high quality,high uniformity and high conductivity is still a subject worthy of study.Recent theoretical studies have shown that multi element co-doping may be a better way to improve the performance of diamond semiconductors.Boron and other elements are incorporated into the diamond crystal to improve its electrical properties.The results show that hydrogen is an excellent co-doping element,which can improve the defects in semiconductor to achieve the purpose of electrical optimization.Therefore,the research on boron hydrogen co doped diamond is of great significance.For this research direction,we study the synthesis of boron and hydrogen co-doped diamond.In this paper,large single crystals of diamond were successfully synthesized by using domestic hexahedral press under high temperature and high pressure.KBH4 was used as additive to provide abundant boron and hydrogen by temperature gradient method.The crystal growth in different catalyst systems was discussed.The results show that different catalysts have great influence on the growth of KBH4 doped diamond.The crystal properties of NiMnCo catalyst are better than that of FeNi catalyst,and NiMnCo catalyst is more conducive to boron entering into diamond than FeNi catalyst.