Thermal‐emission‐rate measurements, including DLTS, have been made on thallium‐doped gated diode structures fabricated using an implanted thallium source. The rate of thermal emission was found to be strongly field dependent, giving results comparable to the prediction of the simple Poole‐Frenkel model. The field‐free trap separation from the valence‐band edge was determined to be 0.24 eV, with a hole‐capture cross section of 2.4×10−14cm2.