Extended near-IR spectral sensitivity and electroluminescence properties of silicon diode structure with GaSb/Si composite layer

摘要

An array of GaSb nanocrystallites (NCs) was formed on Si(001) substrate by solid-phase epitaxy at 500°C. Owing to the embedded GaSb NCs, p~+-Si/NC-GaSb/n-Si mesa diode spectral sensitivity has extended up to 1.6 μm at room temperature, and its integral sensitivity has increased by 4-5% in the wavelength range of 1200-1600 nm, as compared to a conventional Si diode. This result was achieved by embedding only 10 nm of GaSb in the form of NCs inside a silicon matrix. In addition, we could obtain a significant electroluminescence (EL) signal at 120 K in a very wide wavelength range from 1.3 to 2.1 μm (0.95-0.59 eV). The EL spectrum has a broad maximum at 1700 nm (0.73 eV). The threshold pumping current density was as low as 0.75 A/cm~2.