The problem of doping of non-stoichiometric phases
The problem of doping of non-stoichiometric phases
复制标题
DOI：
10.1016/j.jpcs.2007.07.131
复制
发表时间：
2008-02
影响因子：
4
通讯作者：
E. Rogacheva
中科院分区：
文献类型：
--
作者：
E. Rogacheva
概述和分析了我们在掺杂条件下非化学计量比半导体IV-VI相的晶体结构、力学性质、热学性质、电磁性质和电学性质的实验数据。讨论了通过引入元素杂质和通过阳离子取代掺杂这些相的特点和一般规律。与无缺陷的晶体相比，非化学计量空位的存在导致了一种新的杂质溶解机制，即杂质原子占据空位。这一过程伴随着显微硬度和载流子浓度的下降，以及载流子迁移率和晶格热导率的增加。结果表明，杂质的溶度极限值与IV原子的离子半径与杂质的离子半径的相对差之间存在一定的相关性。在阳离子取代下，主体化合物中大量非化学计量缺陷的存在决定了在较小的杂质浓度范围内性质的浓度依赖关系的特异性。变价阳离子的引入导致了一种特殊的效应，这种效应是由非化学计量空位的存在引起的，包括在改变杂质原子浓度或偏离化学计量比的情况下阳离子的重新充电。
An overview and analysis of our experimental data on the crystal structure, mechanical, thermal, galvanomagnetic and electrical properties of the non-stoichiometric semiconducting IV–VI phases under doping are presented. The peculiarities and general regularities of the doping of these phases by introduction of elementary impurities and by cation substitution are considered. The presence of non-stoichiometric vacancies in the cation sublattice of the host compound leads to the appearance of a new, in comparison with a crystal free of defects, mechanism of impurity dissolution consisting in occupation of vacancies by impurity atoms. This process is accompanied by a decrease in microhardness and charge carrier concentration, and an increase in charge carrier mobility and lattice thermal conductivity. It is shown that there is correlation between the value of impurity solubility limit and relative difference in ionic radii of IV atoms and those of the impurity. Under cation substitution, the existence of a large number of non-stoichiometric defects in the host compound determines the specificity of the concentration dependences of the properties in the range of small impurity concentrations. The introduction of cations with variable valence leads to a specific effect caused by the presence of non-stoichiometric vacancies and consisting in the recharging of cations under changing impurity atom concentration or deviation from stoichiometry.