LATTICE COUPLING STRENGTH OF ELECTRON-INDUCED-IRRADIATED DEFECTS IN INP

Optical properties of some electron-induced-irradiated defects inInP, hole traps H//7, H//5, H//4 and electron trap E//1//1, are investigated by means of deep-level-optical-spectroscopy. Both majority and minority photoionization cross-sections measurements of E//1//1 and H//5 are performed, together with direct measurements of the hole capture cross section of H//5. In levels H//7 and H//4 the only majority photoionization cross section could be obtained. Interpretation is made on the basis of one-dimensional coordinate diagrams. From these, it is concluded that levels H//4 and E//1//1 are weakly relaxed while levels H//5 and H//7 are strongly coupled to the lattice. This is a new indication that EII defects in InP can be at least classified into two groups, owing to their microscopic origin and physical properties.