TRAP LEVEL SPECTROSCOPY IN K1-XLIXTAO3

We present results on thermally stimulated current (TSC) spectroscopy in K0.984Li0.016TaO3 and K0.966Li0.034TaO3 single crystals. Observatio ns were made in different poling conditions. Several trap levels were detected in the range 15 K - 310 K. Parameters for the deeper levels w ere derived by the Hoogenstraaten method. Shallow levels (hundredths o f an eV deep) can explain low temperature photocurrent and persistent current phenomena in terms of very efficient hole trapping.