Experimental characterization demonstrates dual acceptor energy levels for gold in germanium, indicating potential utility for infrared photoconductivity.
Key Points
To characterize the electrical, optical, and diffusion behaviors of gold impurities in germanium crystals.
Measured resistivity, Hall effect, and scattering phenomena at temperatures down to 77°K.
Characterized infrared photoconductivity spectra and measured diffusion rates at 900°C alongside heat treatments.
Modeled the temperature variation of the Fermi level and Hall coefficient using Fermi statistics.
Gold acts as a dual-level acceptor producing states at 0.15 eV above the valence band and 0.2 eV below the conduction band.
Gold-doped germanium functions as an infrared photoconductor with wavelength response up to 8 microns and reaches resistivities up to 10^8 ohm-cm at 77°K.
Gold exhibits a solid solubility of ~10^15 atoms/cm³, a segregation coefficient of 1.5×10^-5, and a diffusion coefficient of 4×10^-9 cm²/sec at 900°C with an activation energy of 2.5 eV.