Wide Concentration Range Zn-doping in CuGaS_2 using Atomic Layr Epitaxy and Elucidation of the Role of Zn

通过对CuCl源、(C2H5)5GaCl源和H2S源交替进料条件下在GaP(100)衬底上气相外延生长CuGaS_2的实验研究表明，在交替进料的情况下，CuGaS_2的生长方向为c轴，生长速率为1/8c晶格常数，即1/2单分子层厚度。而在完全分离的交替喂料条件下，生长方向为c轴，生长速率为单层厚度。这些结果被认为与原子层生长相对应。两种金属源之间的H_2S供应对原子层的生长是必不可少的。这一事实表明，两种金属原子的重排是CuGaS_2生长所必需的。在完全分开的交替供电下，锌相关发光的出现与同时供电的锌和铜源以及同时供电的锌和镓的情况有很大的不同。然而，这一事实是否与锌的位置选择性掺杂直接相关，必须考虑到上述两种金属原子的重排可能性。

From experimental investigation of vapor phase epitaxial growth of CuGaS_2 on GaP (100) substrates under alternate feeding conditions using the sources of CuCl, (C_2H_5)_5GaCl and H_2S,the followings became clear.Under separated alternate feeding of metal sources (CuCl, (C_2H_5)_2GaCl) and H_2S,the growth oriented toward c-axis with growth rate per cycle of 1/8 c lattice constant, i.e., 1/2 mono-molecular layr thickness occurs. While under completely separated alternate source feeding, the growth oriented toward c-axis with growth rate per cycle of one mono-layr thickness does. These results are thought to correspond to atomic layr growth. One supply of each source causes one atomic layr growth, and H_2S supply between two kind of metal sources supply is essential for the growth. This fact suggests an occurrence of rearrangement of two kinds of metallic atoms is necessary for the growth of CuGaS_2.Under completely separated alternate source feeding, the appearance of Zn-related luminescence showed big difference between the cases with simultaneous Zn and Cu sources feeding and with simultaneous Zn and Ga sources feeding. However, whether this fact is directly related to site selective doping of Zn or not must be discussed taking into account rearrangement possibility of two kind of metallic atoms described above.