ABSTRACT

Zinc sulphide (ZnS) thin films were synthesised by chemical bath deposition technique without using complexing agent. A physicochemical study was realized on the growth solution composed of ZnCl₂, KOH, and SC(NH₂)₂. The bath solution was at 60°C and pH values of 11.5, 12, and 12.5 were selected for growing the material. The species distribution diagrams, and solubility curves show that the growth mechanism requires the presence of zinc-hydroxide ions, and alkaline pH for growing the ZnS. The physicochemical properties of the samples improve as the pH of the solution increases. Samples deposited at pH=12.5 present a cubic structure (sphalerite) and bandgap energy of 3.72 eV, consistent with bulk-ZnS. For comparison, additional chemical baths were prepared by using NH3 as complexing agent; however, the properties of those samples result inferior. This methodology was validated by depositing ZnS films at 40°C without the complexing agent, obtaining similar results.

摘要

硫化锌（ZnS）薄膜是通过化学浴沉积技术合成的，不使用络合剂。对ZnCl ₂、KOH和SC(NH ₂ ) ₂组成的生长溶液进行了理化研究. 浴液温度为 60°C，选择 11.5、12 和 12.5 的 pH 值来培养材料。物种分布图和溶解度曲线表明，生长机制需要氢氧化锌离子的存在，以及生长 ZnS 的碱性 pH 值。样品的物理化学性质随着溶液 pH 值的增加而改善。在 pH=12.5 下沉积的样品呈现立方结构（闪锌矿）和 3.72 eV 的带隙能量，与块状 ZnS 一致。为了比较，使用 NH3 作为络合剂制备了额外的化学浴；然而，这些样品的性能较差。该方法通过在 40°C 下沉积 ZnS 薄膜而没有络合剂得到验证，获得了类似的结果。