Investigation of Impurity conduction band which formed as a result of interaction of two electron (H--like) impurity states presents a great interest both for physics of irregular systems and for physics of semiconductors. Detailed investigation of the process of the formation of H--band were carried out in [1,2]. However up to now there are not numerous experimental works on H--band because it is rather difficult to separate the conduction on H--band from the other types of conduction.
A. I. Demin, A. I. Demin,
"Time of energy relaxation of carriers in H--band", Proc. SPIE 1576, 16th International Conference on Infrared and Millimeter Waves, 15762C (1 October 1991); doi: 10.1117/12.2297797; https://doi.org/10.1117/12.2297797