Preparation and properties of an integrated system ‘photosensitive heterostructure–semiconductor scintillator’ on the basis of compounds AIIBVI

• Published in: The international journal of inorganic materials 2001-12, Vol.3 (8), p.1223-1225
• Main Authors: Focsha, A.I, Gashin, P.A, Ryzhikov, V.D, Starzhinskiy, N.G
• Format: Article
• Language: English
• Subjects: Detector; Heterostructure; Scintillator; Spectral concordance factor; X-ray dose
• ISSN: 1466-6049; 1466-6049
• DOI: 10.1016/S1466-6049(01)00134-9

Ways of practical realization are studied for a unique property combination found in crystals ZnSe(Te) as semiconductor materials and highly efficient scintillators. It is shown that this combination allows to create heterostructures – photoreceivers of intrinsic luminescence of the scintillator directly on the ZnSe(Te) crystal surface. Methods are considered of preparation of photosensitive structures nZnSe(Te)–pZnTe and ZnSe(Te)/pZnTe–nCdSe using solid-phase substitution reactions and subsequent epitaxial growth on crystals ZnSe(Te) with orientation [110]. For practical applications, the most suitable are combined detectors of ZnSe(Te)/pZnTe–nCdSe type. Optimum thickness of epitaxial p-ZnTe and n-CdSe layers was 6–8 and 18–20 μm, respectively. It has been shown that maximum e.m.f. value for integrated detectors is 1.2–1.4 V, and their X-ray sensitivity reaches values up to 150–200 nA·min/R·cm2. Dynamic linearity range of output characteristics of the detectors was not less than 105, afterglow level after 20 ms – less than 0.05%, allowing to use them in X-ray tomographs.