Investigation On The Interfacial Barrier Of Perovskite Manganite P-n Heterojunction

Duing to the charge, orbital, spin and lattice degrees of freedom correlating witheach other, perovskite manganites have a series of complicated physical properties,which gradually makes it the focus of researchers. Study of manganite-basedheterojunctions has increasingly indicate that it has important research value andapplication potential on the aspect of artificial structure material and microelectronicsdevices. As interfacial barrier plays a key role in the transport process ofmanganite-based heterojunctions, quantitative analysis of the heterojunction interfacebarrier will be an important research subject. We expect that the researches can promotethe further study on the physics and devices of the manganite based heterojunctions.In this thesis, we have systematically studied the electrical transport properties ofmanganite-based p-n heterojunctions, the main contents are as follows:i) Using the traditional solid-state method to fire target and the pulsed laserdeposition technique to grow manganite films on appropriate single crystal substrate,then the manganite-based heterojunction samples were prepared.ii) The structure of the samples was examined by x-ray diffraction (XRD). Thesurface morphology of the samples was examined by transmission electron microscopy(TEM).iii) We studied the rectifying behavior of the junction and the interfacial barrierheight was concluded by analyzing the activation energy.iiii) We calculated the interfacial barrier by analyzing the current-voltage curve,and it was found that the method presented in this paper was more simple and the resultwas more accurate.iiiii) The relationship between interfacial resistance and temperature was furtherstudied, and we found that the present junctions show negative temperature coefficientcharacteristics, satisfying the relation R(T)=R0exp (B/T), and the value of B which affected the sensitivity of thermistor, was very large. The results show that suchheterojunctions can be used for the preparation of highly sensitive NTC thermistor.