Chemical Beam Epitaxy of Compound Semiconductors

Contains reports on three research projects.3M Company Faculty Development GrantAT&T Research Foundation Special Purpose GrantJoint Services Electronics Program Contract DAAL03-89-C-0001National Science Foundation Grant ECS 88-46919National Science Foundation Grant ECS 89-05909Purdue University Subcontract No. 530-0716-07U.S. Navy - Office of Naval Research Contract N00014-88-K-056

Formation and assignment of silver defect centres in phosphate glass induced by femtosecond laser pulses

We have investigated the formation and assignment of silver defect centres such as Ag0, Ag2+ and other molecular silver species induced by femtosecond (fs) laser pulse irradiation. In particular, direct precipitation of silver nanoparticles without heat treatment was demonstrated to clarify the formation kinetics of silver defect centres in a radiophotoluminescent phosphate glass by 250 kHz high repetition rate fs laser pulses. Comparison using X-ray and fs laser irradiation methods is also presented. © 2011 Elsevier Ltd. All rights reserved

The role of silver in the radiophotoluminescent properties in silver-activated phosphate glass and sodium chloride crystal

金沢大学人間社会研究域人間科学系We have systematically investigated the X-ray-induced radiophotoluminescence (RPL) bands in a silver-activated phosphate glass (PG:Ag), and we have ascribed these bands to Ag0, Ag2+ and Ag2+ centres, using optical characterisation such as absorption, excitation, emission and lifetime measurements. The absorption spectrum of PG:Ag irradiated with X-rays was decomposed into six Gaussian bands on the basis of its strong analogy with irradiated silver-activated sodium chloride (NaCl:Ag). We confirmed that blue emission peaking at 450 nm was connected with the 270 and 345 nm bands of the excitation spectrum, while orange emission peaking at 560 nm was associated with the 308 nm excitation band. Each band of the excitation spectrum was in turn attributed to an Ag2+, Ag0 or Ag2+ centre by analogy with the RPL of NaCl:Ag. The excited-state lifetimes for each emissive process were also determined for different X-ray doses. In conclusion, we determined that both blue and orange emissions result from radiation-induced (rather than intrinsic) properties in the range of 1.22-24.5 Gy. © 2010 Elsevier B.V. All rights reserved

Non-destructive readout of 2D and 3D dose distributions using a disk-type radiophotoluminescent glass plate

Novel disk-type X-ray two- and three-dimensional (2D, 3D) dose distributions have been developed using atomic-scale defects as minimum luminescent units, such as radiation- induced silver (Ag)-related species in a Ag-activated phosphate glass. This luminescent detector is based on the radiophotoluminescence(RPL) phenomenon. Accurate accumulated dose distributions with a high spatial resolution on the order of microns over large areas, a wide dynamic range covering three orders of magnitude and a non-destructive readout were successfully demonstrated for the first time by using a disk-type glass plate with a 100-mm diameter and a 1-mm thickness. In addition, the combination of a confocal optical detection system with a transparent glass detector enables 3D reconstruction by piling up each dose image at different depths within the material. © Published under licence by IOP Publishing Ltd

Chemical Beam Epitaxy of Compound Semiconductors

Contains reports on three research projects and a list of publications.3M Company Faculty Development GrantAT&T Research Foundation Special Purpose GrantDefense Advanced Research Projects Agency Subcontract 216-25013Defense Advanced Research Projects Agency Subcontract 542383Joint Services Electronics Program Contract DAAL03-89-C-0001National Science Foundation Grant ECS 88-46919National Science Foundation Grant ECS 89-05909U.S. Navy - Office of Naval Research Contract N00014-88-K-0564Charles Stark Draper Laboratories Contract DL-H-418484Defense Advanced Research Projects Agency Subcontract 530-0716-0