Dember effect induced photovoltage in perovskite p-n heterojunctions

An unusual and rather large transient lateral photovoltage (LPV) has been observed in La0.9Sr0.1MnO3/SrNb0.01Ti0.99O3 and La0.7Sr0.3MnO3/Si heterojunctions under the nonuniform irradiation of pulsed laser. The irreversible LPVs on both sides of a p-n junction challenge the well established model for LPV in conventional semiconductor p-n junctions, which can be well explained by the Dember effect. Much larger LPV is observed in La0.7Sr0.3MnO3/Si than that in La0.9Sr0.1MnO3/SrNb0.01Ti0.99O3. Similar results measured from both substrates of SrNb0.01Ti0.99O3 and Si also support such a Dember effect. Much larger LPVs in heterojunctions than those in simple samples (SrNb0.01Ti0.99O3 or Si) suggest a potential application of Dember effect in heterostructures.