Melting phenomenon and laser annealing in semiconductors

Excess Carrier Phenomenon in Semiconductors

Laser cooling in semiconductors

The recent advances in the development and fabrication of semiconductor lasers have stimulated growing interest in semiconductors as candidates for optical cooling. The essential difference between semiconductors and rare-earth (RE) doped materials is in their cooling cycles. In the case of RE-doped glasses or crystals, the cooling transition occurs in localized donor ions within the host. In t...

Laser Cooling of Semiconductors

Optical irradiation accompanied by spontaneous anti-Stokes emission can lead to cooling of matter, a phenomenon known as laser cooling or optical refrigeration proposed in 1929 by Peter Pringsheim. In solid state materials, the cooling is achieved by annihilation of lattice vibrations (i.e., phonons). Since the first experimental demonstration in rare-earth doped glasses, considerable progress ...

Nanosecond time-resolved reflectivity determination of the melting of metals upon pulsed laser annealing

Thin metal fiIrns (Cu, Au, Ni) on quartz glass were illuminated with nanosecond pulse.; of a frequency doubled Nd:YAG laser (A = 532 nm). The transient reflectivity behavlour was probed at the wavelength 633 nm, where these metals exhibit Drude-Iike optical behaviour: the reflectivity decreases with temperature in the solid and in the Iiquid state as well as at the solid-llquid phase transition...

Pulsed Laser Heating and Melting

Modification of surfaces by laser heating has become a very important aspect of modern materials science. The author’s own interests in laser processing have been involved in the main with laser processing of semiconductors, especially II-VI materials such as CdTe, but also amorphous silicon. Applications of laser processing are diverse and include, in addition to the selective recrystallisatio...