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The physical and electrical properties of ion-implanted silicon annealed with high-powered laser radiation are described. Particular emphasis is placed on the comparison of materials properties that can be achieved with laser annealing to those which can be achieved by conventional thermal annealing. Applications of these techniques to the fabrication of high-efficiency solar cells, and potential applications of this new technique to other materials areas are discussed.

Superconducting YBa2Cu3O7−x (YBCO) films were grown by laser ablation on Ag(001), Ag(110), and Ag(111) single-crystal surfaces. X-ray diffraction measurements showed that, in all cases, the films were aligned with specific in-plane epitaxial orientation with respect to the crystallographic axes of the substrate. The observed orientations were consistent with predictions of near-coincident site lattice models of the YBCO-Ag interface. This technique for achieving three-dimensional film alignment was extended to include a Ag epitaxial buffer layer on mica in place of a bulk Ag crystal. In-plane epitaxial alignment on metal substrates and buffer layers has important consequences in practical applications for inhibiting weak-link behavior caused by high-angle grain boundaries.

The properties of boron-implanted silicon annealed by high-power Q-switched ruby laser radiation are compared with results obtained by conventional thermal annealing. Laser annealing of the implanted layer results in significantly increased electrical activity, as compared to thermally annealed implanted silicon. This correlates well with transmission electron microscopy and ion-channeling measurements which show a dramatic removal of displacement damage as a result of laser annealing. A substantial redistribution of the implanted boron concentration profile occurs after laser annealing which cannot be explained by thermal diffusion in the solid.

Transition to a superconducting zero-resistance state at 155 K is observed for the first time in bulk material. A new five-element compound has been synthesized with nominal composition YiBa2Cu3F20^. Fluorine plays a critical role in achieving this effect. X-ray diffraction and electron microprobe analysis indicate that the samples are multiphasic. Evidence is presented that the samples contain superconducting phases with onset temperatures considerably above 155 K. Magnetic measurements suggest a fluxtrapping effect below 260 K, and diamagnetic deviations from Curie-Weiss behavior in the range 250 K < r< 100 K indicate a Meissner effect in a small superconducting volume fraction.