Spectra of Photoexcitation of Free Excitons by Submi1limeter Radiation in "Ultrapure" Germanium
Vavilov V.S. , Guzeev I.V., Zayats V.A. , Kononenko V.L. , Mandel'shtam T.S. , Murzin V.N.
A series of absorption lines corresponding to transitions from the ground state to excited states of a free exciton in germanium was registered for the first time in a wide submillimeter band (1.7 3-7 meV). The measurements were made at 1.5 4.2°K on a sample with a residual-impurity concentration 5 * 1010 cm-3. Temperature measurements yielded for the splitting of the ground state of the indirect exciton a value Δ ^ 0.7 meV.