Electrical transport properties in Ge hyperdoped with Te

Abstract

In this work we have successfully hyperdoped germanium with tellurium with a concentration peak of 1021 cm−3. The resulting hyperdoped layers show good crystallinity and sub-bandgap absorption at room temperature which makes the material a good candidate for a new era of complementary metal-oxide-semiconductor-compatible short-wavelength-infrared photodetectors. We obtained absorption coefficients α higher than 4.1×103 cm−1 at least up to 3 μm. In this study we report the temperature-dependency electrical properties of the hyperdoped layer measured in van der Pauw configuration. The electrical behaviour of this hyperdoped material can be explained with an electrical bilayer coupling/decoupling model and the values for the isolated hyperdoped layer are a resistivity of 4.25×10−3Ω·cm with an electron-mobility around −100 cm2 V−1 s−1.