Self-assembled infrared-luminescent Er-Si-O crystallites on silicon

Optically active and electrically excitable erbium complexes on silicon are made by wet-chemical synthesis. The single-crystalline Er-Si-O compound is formed by coating a Si(100) substrate with an ErCl3/ethanol solution, followed by rapid thermal oxidation and annealing. Room-temperature Er-related 1.53 mum photoluminescence is observed with a peak linewidth as small as 4 meV. The complexes can be excited directly into the Er intra-4f states, or indirectly, through photocarriers. Er concentrations as high as 14 at. % are achieved, incorporated in a crystalline lattice with a 0.9 nm periodicity. Thermal quenching at room temperature is only a factor 5, and the lifetime at 1.535 mum is 200 mus. (C) 2004 American Institute of Physics.