Bøger af Zahid H Khan

Bulk GaP is an indirect-gap (2.26 eV) semiconductor and is a poor light emitter. Therefore, the crystalline size reduction in the formation of porous GaP is the crucial step towards opto- electronic device applications. Porous GaP based structures possess high luminescence efficiency across the wide range from green-blue to UV spectrum. The laser-induced etching process has the added advantage of a control of size and optical properties without needing the use of electrodes. The laser-induced etching process is a promising technique for fabricating many optoelectronic devices including: light emitter devices, detectors, sensors and large-scale integrated circuits. The surface phonon frequency depends on the nanocrystalline size, shape and dielectric constant of the surrounding medium.The average crystallite size was estimated to be 3nm. The broadening of Raman line is caused by the size distribution, which is dependent on the etching parameters.