Band-Structure Modification by Insertion of Small Atoms at Tetrahedral Interstitial Sites in Zinc-Blende-Like Lattice

ZnP可以看作是一种部分填充了He-like Li^+间隙的ZnP -晶格。在钽坩埚中定向凝固Li、Zn、P，制备了LiZnP。生长的晶体呈透明红色，呈反萤石结构，a=5.765<正负> 0.00a。差热分析表明，在950^ C附近存在吸热反应，表明晶体的熔点或分解。在295 ~ 95 K的温度范围内，LiZnP被证实为直接带隙为2.04 ~ 2.12 eV的半导体。除部分晶体外，生长晶体均为p型。室温下的典型电阻率、霍尔迁移率和载流子浓度分别为10^<-1>-10 OMEGAcm、1-10 cm^2/Vs和10^<16>-10^<18> cm^<-3>。利用光致发光（PL）技术研究了在77K下LiZnP中与天然缺陷相关的辐射重组。一种类型的PL发射由两个峰组成：一个是615nm （2.02 eV）与磷空位（位于导电带以下110meV） -价带跃迁有关的峰，另一个是848nm （1.46eV）与磷空位-受体复合物有关的宽峰。另一种类型仅在830nm左右表现出宽发射。在两种类型中观测到的广泛排放的来源可能在本质上是相同的。

LiZnP can be viewed as a zinc-blende-like (ZnP)^- lattice filled partially with He-like Li^+ interstitials. We have grown LiZnP by directional solidification of Li, Zn, and P using a tantalum crucible. The grown crystals were transparent red in color and showed the antifluorite structure with a=5.765<plus-minus>0.005A. The differential thermal analysis show an endothermic reaction around 950^ﾟC, indicating the melting point or the decomposition of the crystal. LiZnP was confirmed to be a semiconductor with direct band gap 2.04 to 2.12 eV at a temperature ranging from 295 to 95 K. As grown-crystals are p-type except for some crystals. The typical resistivity, Hall mobility, and carrier concentration at room temperature are of the order of 10^<-1>-10 OMEGAcm, 1-10 cm^2/Vs and 10^<16>-10^<18> cm^<-3>, respectively. The radiative recombination related to a native defect in LiZnP was studied at 77K using photoluminescence (PL) technique. One type of PL emission consists of two peaks : One is a peak 615nm (2.02 eV) associated with a phosphorus vacancy (lying at 110meV below the conduction band) -valence band transition and the other a broad peak at 848nm (1.46eV) associated with phosphorus vacancy-acceptor complex. Another type exhibits an only broad emission around 830 nm. The origin of the broad emissions observed in both types is likely to be identical essentially.