Structural and optical characterization of hole-doped Ge/SiGe multiple quantum wells for mid-infrared photonics

Abstract

The structural and optical properties of p-doped Ge quantum wells separated by SiGe barriers are presented. The composition profile was determined by atom probe tomography and X-ray diffraction measurements. The energy and broadening of the fundamental intersubband transition were studied by Fourier transform infrared spectroscopy which revealed a strong absorption peak around 8.5 μm making this or similar heterostructures suitable for the realization of optoelectronic devices working in the fingerprint region.