Zn-rich Cu x Zn y S is a transparent p-type semiconductor. We prepared Cu x Zn y S thin films by the photochemical deposition method and investigated changes in their properties due to annealing. The sample before annealing was amorphous, and its composition was Cu: Zn: S: O = 0.04: 0.51: 0.31: 0.14. The band gap was estimated to be about 3.5 eV by optical transmission measurement. P-type conductivity was confirmed by the photoelectrochemical measurement. After annealing at 400 ºC for 1 h, the formation of the ZnS phase was observed by X-ray diffraction measurement. Although the band gap did not change significantly, the conduction type became close to intrinsic.

SUMMARY NiO is a p‐type semiconductor having a large band gap (>3 eV). In this study, thin films containing Ni‐O were deposited by the cathodic electrochemical deposition method, and characteristics change by heat treatment was investigated. An aqueous solution containing Ni(NO3)2 was used as a deposition solution. X‐ray photoelectron spectroscopy showed that the sample before annealing was predominantly Ni(OH)2. After heat treatment in air at temperatures higher than 300 °C, the NiO phase was observed by X‐ray diffraction, and the p‐type response was confirmed by the photoelectrochemical measurement. The band gap obtained from the light transmittance measurement was around 3.5 eV.

No abstract

Zn-rich CuxZnyS is a transparent p-type semiconductor. In this study, we fabricated CuxZnyS thin films by electrochemical deposition and investigated changes in properties due to annealing in a sulfur atmosphere. The sample before annealing was amorphous with composition Cu : Zn : S : O = 0.03 : 0.29 : 0.57 : 0.11. After one hour annealing at 400ºC, we observed formation of the ZnS phase by X-ray diffraction and Raman measurements. Although the sample exhibited p-type conductivity before the annealing, it did not clearly show p-type conductivity after the annealing at temperatures higher than 300ºC. Those results indicate that CuxZnyS is a metastable phase and is believed to separate into the ZnS phase and a phase including Cu by the annealing at temperatures higher than 300ºC.