Study of carrier behavior in La0.9Ba0.1MnO3 − δ/SrTiO3:Nb p-n heterojunction

The p-n junctions had been fabricated by depositing La0.9Ba0.1MnO3 − δ (LBMO3 − δ) thin film on the Nb-doping SrTiO3 (STON) substrates. Good rectifying properties of the LBMO3 − δ/STON p-n junction have been confirmed in the temperature range of 70–300 K. It is found that the photovoltage (Voc) peaks increase with increase of laser energy and temperature. The thermal excitation effects and the reduction of conduction-band mismatch with the rising of temperature are suggested to be responsible for the more carriers accumulating at edges of depletion layer, as well as the enhanced Voc peak.