A New Technique of Compound Semiconductor Deposition from an Aqueous Solution by Photochemical Reactions

Abstract

CdS films were successfully formed on a glass substrate in an aqueous solution containing S2O3 2- and Cd2+ ions by photochemical reaction. S2O3 2- ions in the growth solution absorb ultra-violet light of wavelengths shorter than about 300 nm, and the excited S2O3 2- ions supply sulfur atoms and electrons to the metal ions such as Cd2+. Thus, the formation reaction of the sulfide semiconductor occurs in the only illuminated region. Photochemically deposited CdS thin films were polycrystalline of hexagonal structure. The composition of the films became stoichiometric by the annealing at temperatures higher than 300° C.

Deposition of ZnS1‐xOx thin films by the photochemical dip coating method and application for heterojunction solar cells

“…The reaction of sulphide formation under the UV irradiation is thought to be the same as in the previously reported photochemical deposition of sulphides [1,2]. The solution absorbs UV light with wavelength shorter than about 300 nm, and ZnS is formed from Zn 2+ ions and elemental sulphur dissociated from S 2 O 3 2-ions under UV irradiation.…”

“…In electrodeposition, films can be deposited only on a conductive substrate. We developed another chemical technique of thin film deposition, that is, photochemical deposition [1,2]. The substrate is immersed in the solution and irradiated by UV light.…”

Templated Synthesis of CdS/PAN Composite Nanowires under Ambient Conditions

“…The results of the former showed that the CdS nanocrystallines synthesized under these conditions were nearly spherical and formed primarily by aggregation of CdS nanoparticles. Similar reactions have been described in which CdS films were successfully deposited on a glass substrate in an aqueous solution illuminated by a low-pressure mercury lamp; the solution contained only S 2 O 2− 3 and Cd 2+ ions (24). However, the latter yielded no polymer under similar conditions.…”

New Principles in Design and Technology of Multi-junction Solar Energy Converters

“…The PCBD technique was described earlier [13], [14], and used for deposition of semiconductors like CdS and ZnS. In these previous papers, the deposition process was not possible without UV illumination; in our case, the deposition without illumination is possible, but with much slower rate.…”