Hg1-xCdxI2/CdTe-based heterostructures as a new high Z material for radiation detectors: VPE growth of micro-pixel arrays

Abstract

Hg1-xCdxI2 and CdTe belong to the high Z, wide band gap semiconductor compounds of the type II-VII2 and II-VI, respectively. CdTe is a well-known material for the fabrication of nuclear radiation detectors operating at room temperature (direct converter), and Hg1-xCdxI2 (scintillator material) has the eventual functional attraction represented by the fact that its binary precursors HgI2 and CdI2 have a large difference in the band gap values (2.37 and 3.48 eV at 4.2 K, respectively) which allows the alloy band gap variation in the about 1 eV region. The present paper demonstrates new important technological advantage of Hg1-xCdxI2/CdTe-based heterostructures such as the possibility of selective area vapour phase epitaxy (VPE) growth to form micro-pixel arrays of this material on commercial glass substrates. © 2006 Elsevier B.V. All rights reserved.