Nonlinear energy-selective nanoscale modifications of materials and dynamics in metals and semiconductors

Studies of nonlinear, energy-selective material interactions localized at s urfaces, heterointerfaces, impurities, and defects in solids are described. Particular reference is made to a new molecular interaction effect caused by transfer of surface energy by low-energy collisions, a new noncontact no nlinear optical method of studying electron and hole dynamics at a heteroin terface, and a new approach using a free-electron laser developed at Vander bilt University to activate hydrogen-passivated dopants in silicon. In each case the unique characteristics of particle and photon beams, optimized fo r the technology, were used to extend the range of applications of these ne w energy-selective techniques to solve fundamental and applied problems. (C ) 1999 American Institute of Physics. [S1063-7842(99)01709-2].