Abstract
During the open circuit voltage decay (OCVD) in a diode with τBE≫1 (τB and τE are the lifetimes of the minority carriers in the base and emitter, respectively), the quasistatic approximation is found to be valid in the emitter but not in the base. If the band‐gap narrowing ΔEg is significant, τEB, as well as ΔEg determine the OCVD for tB. For t≫τB [and exp (qV/kT)≫1] OCVD vs t plot is approximately linear with its slope ∼1/τB, irrespective of the magnitude of ΔEg.