Carrier Lifetime of Au-Hyperdoped Ge using Terahertz Spectroscopy

Gold-hyperdoped germanium extends the photodetection beyond the cut-off wavelength of germanium into the infrared wavelengths. Ion implantation followed by pulsed-laser melting process makes a single crystal material with ultrahigh dopant concentrations. The laser parameters influence the dopant's atomic position which leads to different light absorption and carrier transport properties. Time resolved terahertz spectroscopy is used to evaluate the charge carrier lifetime which gives an insight into the defect energetics and atomic location.