The effect of band-tail states on the thermal stability of the infrared stimulated luminescence from K-feldspar

► We investigated the thermal stability of IRSL signal from a sedimentary K-feldspar. ► The isothermal decay of IRSL can be described by considering the band-tail states. ► We obtained a trap depth of ∼1.92 eV for the IRSL stimulated at 50 °C. ► We estimated a band width of ∼0.35 eV for the band-tail states. ► We obtained a trap depth of ∼2.06 eV for the post-IR IRSL at elevated temperature.