Photocarrier injection effect and p-n junction characteristics of La0.7Sr0.3MnO3/ZnO and Si heterostructures

The authors report the fabrication of p-n junctions, consisting of p-type La0.7Sr0.3MnO3 (LSMO) and either n-type ZnO grown on sapphire or n-type Si substrates. The LSMO/ZnO junction exhibits excellent rectifying behavior over the temperature range of 77-300 K with breakdown voltage less than -10 V. LSMO/Si displayed p-n junction characteristics over a temperature region of 77-360 K. Inserting a SrTiO3 layer between LSMO and Si remarkably improved the junction characteristics. All junctions show photocarrier injection effect, illustrating the control of transport properties of LSMO in which electron injection decreases hole concentration following the photoexcitation of both ZnO and Si. (c) 2006 American Institute of Physics.