Mapping of photoelectric effects in semiinsulating CdTe

The main advantage of CdTe and CdZnTe materials is the fact that the envolving elements have big atomic numbers and density, this is reflected in a high absortion coeficient. which is a very preferent feature. It enables to detect low energy photons and means high quantum effiency. Mentioned features can be managed at room temperature, therefore these matrials are very perspective for gamma-ray detection. For the detector sensitivity is important to have low dark current, and to have big fold of carrier lifetime and mobility. These properties can be reached in some parts of the materials. Finding the causes of these quality degradation and the signal loss are the main priorities of the exploration. The main problem is the quality of these materials, the inhomogenities are decreasing the detection capability. In this work we will study lux-amper characteristics and analyze photoconductivity maps to better our understanding how inhomogenities influence these parameters. Two main methods will be used, contactless and contact methods with Au applied as contact metal. These maps will be compared. Photoconductivity maps can increase our understanding of charge transport inside the material