EFFECTS OF AN EXTERNAL MAGNETIC-FIELD ON SHALLOW DONOR LEVELS IN SEMICONDUCTORS

An extension of Faulkner's method for the energy levels of the shallow donor in silicon and germanium at zero field is made in order to inve stigate the effects of a magnetic field upon the excited states. The e ffective-mass Hamiltonian matrix elements of an electron bound to a do nor center and subjected to a magnetic field B, which involves both th e linear and quadratic terms of magnetic field, are expressed analytic ally and matrices are solved numerically. The photothermal ionization spectroscopy of phosphorus in ultrapure silicon for magnetic fields pa rallel to the [1,0,0] and [1,1,1] directions and up to 10 T is explain ed successfully.