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.