Herein, the authors have derived expressions for the rate of emission and mean energy of photoelectrons emitted from the surface of a charged irradiated spherical particle, based on DuBridge theory, and compared the results with those obtained on the basis of Fowler’s theory. These expressions involve Wa, ν, and ξ = (hν – φ)/kT, in contrast to a single parameter, ξ, in Fowler’s theory. It is seen that there is significant difference between the prediction of the two theories on the dependence of rate of emission and corresponding mean energy of photoelectrons on the surface potential.