PHOTOINDUCED CHANGES OF HYDROGEN-BONDING IN SEMIINSULATING IRON-DOPEDINDIUM-PHOSPHIDE

After illumination with 1-1.3 eV photons during cooling-down, metastab le PH modes are observed by IR absorption at 5 K in semi-insulating In P:Fe. They correlate with the photo-injection of holes, but not with a change of the charge state of the K-related centres present at equili brium. They are explained by a change of the bonding of H, induced by hole trapping, from IR-inactive centres to PH-containing centres, stab le only below 80 K. One metastable centre has well-defined geometrical parameters and the other one could be located in a region near from t he interface with (Fe,P) precipitates.