Existence and Binding Energy of the Excitonic Ion

Abstract

Abstract It is shown that the excitonic ion should be stable for any value of the electron to hole effective mass ratio u. An accurate calculation of the binding energy is also performed, in excellent agreement with the values previously obtained in the limiting cases σ = 0 and σ = 1. In particular, the involved binding energy in copper halides is large enough to lead to an observable effect.