Far-Infrared Magneto-Absorption of Bound Excitons in Zinc Doped Germanium

Abstract
Bound exciton in zinc doped germanium is observed in far-infrared magneto-absorption measurement. The spectrum is well explained by a donor-like model. The absorption is due to excitation of an electron from “1s” ground state to “2p±” excited state. It thus gives information on the odd parity states of the complex that is inaccessible in a photoluminescence experiment. The lifetime of a bound exciton is 0.8 µs at 4.2 K in the magnetic field of 2 T.