PREDICTIONS OF THE ONSAGER THEORY BASED ON AN EXPONENTIAL-DISTRIBUTION OF ELECTRON-HOLE SEPARATION DISTANCES

An analytic expression for the free-carrier photogeneration efficiency is derived which is based on the Onsager theory of geminate recombination. The expression assumes that the initial distribution of thermalized electron-hole pairs is described by the function g (r) = (1/4πr2b) exp(-r/b), where r is the electron-hole separation distance and b is a dispersion parameter. An evaluation of the electric field and temperature dependences of the photogeneration efficiency is described. A comparison of results obtained with exponential and δ function distributions is presented and discussed.