Time-resolved photoluminescence study of the red emission in nanoporous SiGe alloys

• Published in: Journal of luminescence Vol. 80; no. 1; pp. 153 - 157
• Main Authors: Lebib, S, von Bardeleben, H.J, Cernogora, J, Fave, J.L, Roussel, J
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.1998; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Nanoporous; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Photoluminescence; Physics; Porous materials; SiGe alloy; Time-resolved PL; SiGe alloy; Time-resolved PL; Nanoporous; Photoluminescence; Inorganic compounds; Semiconductor materials; Line shape; Oxide layer; Porous materials; Binary compounds; Etching; Nanostructures; Experimental study; Germanium compounds; Anodization; Luminescence decay; Silicon compounds; Time resolution; Lifetime; Quantity ratio; Passivation
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/S0022-2313(98)00087-8

Porous Si 1− x Ge x (PSiGe) layers with efficient room temperature visible photoluminescence (PL) were elaborated by anodical etching from p-type doped epitaxial layers with Ge contents from 5 to 30%. The luminescence is characterised by a broad PL band centred at 1.8 eV. Time resolved photoluminescence decay is studied in porous silicon germanium as a function of germanium content, temperature, emission energies and surface passivation. The PL decay line shape is well described by a stretched exponential in all cases. The effective lifetime at low temperature in as prepared porous Si 1− x Ge x is 400 μs, i.e. an order of magnitude less than in porous silicon. After the formation of a 20 Å thick oxide surface layer we observe a decrease of the effective lifetime to 20 μs at T=4 K.