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

通过对CuCl源、（C_2H_5）_5GaCl源和H_2S源交替加料条件下，在GaP（100）衬底上气相外延生长CuGaS_2的实验研究，明确了以下几点：（CuCl，（C_2H_5）_2GaCl）和H_2S，生长取向为c轴，每周期生长速率为1/8c晶格常数，即，出现1/2的单分子层厚度。而在完全分开的交替源馈电下，以一个单层厚度为周期的生长速率向c轴方向生长。这些结果被认为对应于原子层生长。每种源的一次供给引起一个原子层的生长，并且在两种金属源供给之间供给H_2S是生长所必需的。这一事实表明，CuGaS_2的生长需要两种金属原子发生重排。在完全分开的交替源馈电下，Zn和Cu源同时馈电与Zn和Ga源同时馈电的情况下，Zn相关发光的出现有很大的不同。然而，这一事实是否与锌的位点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来讨论。

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.