Miniband-related 1.4–1.8 μm luminescence of Ge/Si quantum dot superlattices

The luminescence properties of highly strained, Sb-doped Ge/Si multi-layer heterostructures with incorporated Ge quantum dots (QDs) are studied. Calculations of the electronic band structure and luminescence measurements prove the existence of an electron miniband within the columns of the QDs. Miniband formation results in a conversion of the indirect to a quasi-direct excitons takes place. The optical transitions between electron states within the miniband and hole states within QDs are responsible for an intense luminescence in the 1.4–1.8 µm range, which is maintained up to room temperature. At 300 K, a light emitting diode based on such Ge/Si QD superlattices demonstrates an external quantum efficiency of 0.04% at a wavelength of 1.55 µm

Silicon/Germanium Strained-Layer Superlattices

High quality Si/Ge strained layer superlattices are achieved by low temperature molecular beam epitaxy on Si, SixGe1−x and Ge substrates. Various characterization techniques are used to obtain information on critical thickness, strain distribution, misfit dislocations, interface sharpness and superlattice periodicity. The band structure is strongly influenced by strain and zone folding effects. Two-dimensional electron systems can be realized in the wider gap Si layers due to the strain-induced lowering of the conduction band. New optical transitions in the infrared regime are observed with short period Si/Ge superlattices

Entwicklung halbleitender Diamantschichten und deren Qualifikation als Material fuer aktive elektronische Bauelemente Abschlussbericht

Available from TIB Hannover: F98B1229+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman