Electroluminescence and photoconductivity of GeSi heterostructures with self-assembled islands in the wavelength range 1.3–1.55 μm

The effect of structure parameters on the electroluminescence and photoconductivity of multilayer p–i–n structures with self-assembled Ge(Si)/Si(0 0 1) islands has been studied. The highest intensity of the room-temperature electroluminescence in the wavelength range 1.3–1.55 μm has been observed for the islands grown at 600 °C. The observed growth of the electroluminescence signal from the islands with an increase of the Si space layer thickness is associated with a decrease of elastic strain in the structure with thicker space layers. The highest external quantum efficiency of the electroluminescence from the islands in the wavelength range 1.3–1.55 μm amounts to 0.01% at room temperature. The same diode structures with Ge(Si)/Si(0 0 1) islands have demonstrated room-temperature photoconductivity signal in the wavelength range 1.3–1.55 μm. The observed overlap of the electroluminescence and photoconductivity spectra obtained for the same structures with Ge(Si) islands makes these structures a promising material for fabrication of Si-based optocoupler.