Comparison of characterization methods for CdTe/ CdZnTe radiation detector materials and development of an automated test system
Single crystal cadmium telluride (CdTe) and cadmium zinc telluride (CZT) are semiconductors with a suitable band gap to operate as room temperature radiation detectors with low noise. The growth process of these materials is not fully understood, which results low detector quality and production yields and consequently high prices. The current quality assurance techniques used in research and indus-try cannot provide the required information to overcome these issues, nor provide insight into the yet to be understood processes of growth. A more detailed characterization of the material as well as new methods to trace back and improve processes that occur during growth are presented in this thesis. The research and development described in this thesis concentrate on a novel, automated test system tailored to characterize semiconductor crys-tals such as CdTe/ CZT. This system allows to test CdTe/ CZT crystal at an early production stage, when only little resources were used and together with the information of the crystals origin, growth parameters can be ana-lyzed as well as improvements for the growth-process can be identiﬁed.