Thermally Assisted Photoemission of CeB6 at High Temperatures

Photocurrent of CeB6 was measured over wide range of temperature. The photocurrent at high temperature exceeds the value expected by the Fowler-DuBridge theory. A transmission coefficient was introduced to the photoemission equation in order to account for electron escape probability. The fitting of measured data reveals that the transmission coefficient can not explain the rise in photocurrent at high temperatures for different photonenergies.