A ceramic mercuric iodide X-Ray sensor probe is developed from highly pure mercuric iodide. Probe has
high mechanical and chemical stability. Photoconductivity and stability are studied and analysed. It is
found that dark current shows a pure resistive variation with increase in bias voltage where as
photocurrent shows a sigmoidal behavior. Annealing in air helps in reducing the polarization effect and
improving the sensor properties. Adsorption of iodine is found to drastically reduce sensor performance.
Annealed probe shows a repetitive trend in switching characteristics.