MULTIPHONON-ASSISTED ENERGY-TRANSFER BETWEEN YB 4F SHELL AND INP HOST

The energy transfer mechanism between an Yb 4f shell and an InP host w as investigated, assuming that a nonradiative multiphonon process assi sts the energy transfer. The values of the energy involved in the ener gy transfer were determined from the results of optical and electrical experiments. Rate equations were solved to obtain the temperature dep endence of the Yb intra-4f-shell luminescence decay time. The calculat ed results and the experimentally obtained temperature dependence agre e well. The calculated temperature dependence of the Yb intra-4f-shell luminescence intensity also agrees with the experimental measurements . These results strongly suggest that phonon absorption and emission c ompensate tile energy mismatch in the energy transfer processes. The c alculations also indicate that the thermal quenching phenomenon is mai nly determined by the energy mismatch between the recombination energy of an electron and a hole and the Yb 4f-shell energy between the exci ted and ground states. On the basis of the above formulation, the Yb i ntra-4f-shell luminescence intensity under hydrostatic pressure was al so investigated theoretically and compared with experimental results. The 4f-shell luminescence recovery at elevated temperature under hydro static pressure was qualitatively explained in the framework of the pr esent model. The characteristic behavior of the thermal quenching in o ther rare-earth doped semiconductors could also be explained qualitati vely assuming that the energy transfer mechanism is similar to the one for InP:Yb. (C) 1994 American Institute of Physics.