BISMUTH QUANTUM-WIRE ARRAYS FABRICATED BY A VACUUM MELTING AND PRESSURE INJECTION PROCESS

Ultrafine bismuth nanowire arrays were synthesized by injecting its li quid melt into nanochannels of a porous anodic alumina template. A lar ge area (1 cm x 1.5 cm) of parallel wires with diameters as small as 1 3 nm, lengths of 30-50 mu m, and packing density as high as 7.1 x 10(1 0) cm(-2) has been fabricated. X-ray diffraction patterns revealed the se nanowires, embedded in the insulating matrix, to be essentially sin gle crystalline and highly oriented. The optical absorption spectra of the nanowire arrays indicate that these bismuth nanowires undergo a s emimetal-to-semiconductor transition due to two-dimensional quantum co nfinement effects.