PHOTOLUMINESCENCE AND PROBE EFFECT OF ER-DOPED NANOMETER-SIZED SI MATERIALS

Er was doped into porous Si and nanocrystalline Si thin films. Sharp a nd intense photoluminescence at 1.54 mu m was observed up to room temp erature. We demonstrate that Er3+ ions are excited by an energy transf er process from the excited electron-hole pairs in the host materials and no direct excitation of Er3+ ions can be observed. This fact sugge sts that the Er emission could be used as a probe to determine absorpt ion edges of:he hosts. This idea was first applied to Er-doped porous Si. Identical excitation edges of the 1.54 mu m emission and the visib le emission from porous Si have been demonstrated, We suggest that the method should also be valid for measuring the absorption edge of a na nometer-sized Si host material even if it is not luminescent.