Calorimetrische Absorptionsspektroskopie (Cas) - Eine Neue Methode Zur Charakterisierung der Optischen Eigenschaften von Halbleitersystemen (Calorimetric Absorption Spectroscopy (CAS): A New Method for the Characterization of the

摘要

An apparatus for calorimetric absorption spectroscopy (CAS) and calorimetric transmission spectroscopy (CTS) at temperatures up to 1.3K, including computer control, data acquisition, and data evaluation, was built. At 1.3K, products of absorption coefficient and sample thickness up to 0.00001 can be determined with conventional light sources, with a time constant of 1 sec. It is shown that CAS is an efficient technique for the characterization of semiconductors and for the investigation of basic physical phenomena. Parameters which are relevant for the production process, and quantum efficiencies (using CTS) can be determined. The CAS experiments can be used for the study of mainly radiationless recombining centra in solid state materials, revealing fine structures.