The surface morphology of monocrystalline Si(111) implanted by a N10+ cluster ion of 76keV at a dose of 1.7×1017cm-2 was observed using a scaning probe microscope. It was found that the implantated layer directly transformed from monocrystalline into a nanocrystal structure in this condition and its crystallite dimension was also measured. The infrared absorption experiment indicated that the samples intensely and uniformly absorbed infrared light of both near and far infrared regions with a very wide frequency band

and the transmission of about 10% was always kept. The preliminary study indicated that an excellent light absorption material was formed in the implanted layer.