| dc.description.abstract | In this experiment, a series of different ratios of CuInZnS films were prepared by spray pyrolysis method, and their photoelectrochemical properties were measured. However, since CIZS films are composed of four different elements at the same time, the composition is too complicated and it is difficult to find the best photoelectrochemical properties, so experiments developed mainly divided into two parts, the first part : Preference is given to producing CIS films with the best photoelectrochemical properties, and this part has been completed by the graduated Ph.D., Yang Kaixuan. seniors . The second part is to fix the ratio of copper, indium and sulfur in the previous precursors, and to investigate the changes in photoelectrochemical properties at different [Zn]/[In] ratios.
The experimental results shows that with the increase of the proportion of zinc in the precursor, CIZS can be observed that the main signals are shifted to a high angle in the XRD pattern analysis, so it is proved that CuInS2-ZnS solid solution is produced, and its energy gap value also changed from 1.45 eV to 2.1 eV. In photoelectrochemical properties, the CIZS film with [Zn]/[In]=2.4 has a photocurrent density of up to 2.51 mA/cm2 at a voltage of -0.752 V vs RHE and an electrolyte of 0.5 M K2SO4 (Ph=6.8).From results of Mott-Schottky, it can be found that the conductive properties are not changed by the addition of zinc, and all exhibit p-type conductive properties. The CIZS film with [Zn]/[In]=2.4 has a 90% photocurrent performance after one hour of stability test under the applied bias voltage of -0.152 V vs RHE. The photoelectric conversion efficiency (IPCE) at different [Zn]/[In] ratios was used to investigate the photoelectricconversion of CIZS films under various wavelengths of light sources after changing the UV-vis absorption.
In addition, we also sprayed n-type In2S3 on the surface of the CIZS film by spray pyrolysis to do the surface modification. It is expected to produce a film with CIZS/In2S3 p-n juction and use Pt as a co-catalyst to improve the photoelectrochemical properties. Compared with the CIZS film without Pt, the over potential of the CIZS/Pt film is significantly reduced, However, the CIZS/In2S3 film test results did not achieve our expected , so in the subsequent electrochemical experiments, we also tried different methods to discuss the reasons. | en_US |