For the determination of the trap depth from thermoluminescence and thermally stimuated current‐glow curves commonly the initial‐rise method by Garlick and Gibson is used. This method provides accurate results only if the conditionRh(T0)[2/z−1] ≤f(T0) is fulfilled.Ris the retrapping factor,zthe filling ratio of the traps at the temperatureT0,fthe concentration of unoccupied recombination centers, andhthe density of trapped electrons.