LOCAL PROBE TECHNIQUES FOR LUMINESCENCE STUDIES OF LOW-DIMENSIONAL SEMICONDUCTOR STRUCTURES

With the rapid development of technologies for the fabrication of, as well as applications of low-dimensional structures, the demands on cha racterization techniques increase. Spatial resolution is especially cr ucial, where techniques for probing the properties of very small volum es, in the extreme case quantum structures, are essential. In this art icle we review the state-of-the-art in local probe techniques for stud ying the properties of nanostructures, concentrating on methods involv ing monitoring the properties related to photon emission. These techni ques are sensitive enough to reveal the electronic structure of low-di mensional semiconductor structures and are, therefore, able to give de tailed information about the geometrical structure, including fabricat ion-related inhomogeneities within an ensemble of structures. The loca l luminescence probe techniques discussed in this review article can b e divided into four categories according to the excitation source: (i) spatially localized microphotoluminescence spectroscopy using either strong focusing or masking; (ii) near-field optical microscopy to reac h below the diffraction limitation of far-field optics, by either exci ting, detecting, or both exciting and detecting in the near field; (ii i) cathodoluminescence using focused energetic electrons in an electro n microscope; and (iv) scanning tunneling luminescence, using low-ener gy electrons injected or extracted from the tip of a scanning tunnelin g microscope. (C) 1998 American Institute of Physics. [S0021-8479(98)0 8615-0]