Rectifying the Current-Voltage Characteristics of a LiNbO sub(3) Film/GaN Heterojunction

Epitaxial LiNbO sub(3) (LNO) films are grown on n-type GaN semiconductor substrates, forming LNO/GaN p-n junctions. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the junctions are studied. The I-V curve shows a clear rectifying property with a turn-on voltage of 2.4 V. For the forward voltages, the conduction mechanism transits from Schottky thermionic emission for low voltages to space-charge-limited current, for large voltages. Reverse C-V characteristics exhibit a linear 1/C super(2) versus V plot, from which a built-in potential of 0.34 V is deduced. These results are explained using the energy-hand structure of the LNO/GaN junction.