Crystal structure and bonding in the high-pressure form of fluorite (CaF2)

An attempt is made to propose theoretical models for the density-of-states function of heavily doped semiconductors in the presence of quantizing magnetic fields. The results are more general than those of others. The band-tailing in the density of states has been clearly shown in the analyses of M.I. Dyakonov, A.L. Efros, D.L. Mitchell, Phys. Rev. 180 (1969) 813 and ourselves. In the present communication we have formulated the electron energy spectrum for heavily doped semiconductors having unperturbed parabolic bands forming band tails in the presence of a quantizing magnetic field which is, in turn, the key in analyzing the electronic properties of heavily doped semiconductors under quantization of band states. From our generalized results we can obtain different models for the density-of-states in the band-tailing condition. The present model is expected to agree better with the experiments and finally it may be remarked that a singularity has been observed in the density-of-states function in the forbidden region, a phenomenon never observed earlier.