POROUS SILICON AS LOW-DIMENSIONAL HOST MATERIAL FOR ERBIUM-DOPED STRUCTURES

A low-dimensional matrix of porous silicon (PS) was found to be an eff ective host material for erbium (Er) electrodeposition from Er(NO3)(3) . 5H(2)O/ethanol solution. After thermal annealing at 850-1200 degree s C in an O-2-containing atmosphere, such material exhibited sharp 1.5 4 mu m luminescence at 77 K and 300 K. In contrast to previous studies , strong Er-related photoluminescence (PL) was found not only in the c ase of red-emitting PS formed in initial p-Si(111) wafers of 0.3 Ohm c m resistivity but also for micro-sized material formed in initial 0.01 Ohm cm n(+)-Si(111). Erbium doping of p-type PS resulted in a 1.54 mu m peak appearance in addition to two broad PL bands at about 1.3 mu m and 0.8-0.9 mu m. In contrast, n(+)-type PS:Er exhibited only a sharp 1.54 mu m peak without other PL bands. The intensity of the Er-relate d peak depended strongly on the Si anodization regime and increased wi th the PS thickness growth from 1 to 20 mu m Application aspects of PS :Er for light-emitting devices and integrated optical waveguides are d iscussed. (C) 1997 Elsevier Science S.A.