Intense photoluminescence from amorphous tantalum oxide films

Tantalum oxide films were deposited on silicon substrates at a temperature of similar to 450 degrees C by heating a pure tantalum foil in a rough vacuum. The. films were amorphous in structure and consisted of fully oxidized Ta2O5 and (TaOx, x < 2.5) suboxides. This feature resulted in strong visible light emission from the films further oxidized in the air at temperatures of 200-300 degrees C. The mechanism for this photoluminescence behavior of the amorphous tantalum oxide films was also investigated and discussed. This study suggests that wide-band-gap materials could act as effective visible light emitters and provides a simple route to synthesize such materials. (c) 2006 American Institute Of Physics.