I recommend you to measure the Hall effect of ITO separately and then by using the two layers model calculate the Hall parameters of CdZnS layer.

Thanks for your response, these are helpful to me.

It is feasible to do the measurement, provided that the doping level of CdZnS is high enough that the film physical thickness is greater than the P-N junction depletion depth on the CdZnS film side plus the surface depletion depth.

In addition, the defect density must not be too high for a crystalline film to prevent excessive leakage current.