A heterojunction with good rectifying properties in a wide temperature range from 20 K to 300 K was fabricated simply by depositing an as-grown La<sub>0.9</sub>Hf<sub>0.1</sub>MnO<sub>3</sub> (LHMO) film on a commercial 0.7 wt% Nb-doped SrTiO<sub>3</sub> single crystal substrate using pulsed laser deposition technique. The current-voltage behavior of the LHMO/STON is measured under applied magnetic fields varying between 0 and 5 T. The heterojunction shows a remarkable magnetoresistance which depends on both the temperature and bias voltages. The sign of the magnetoresistance as function of temperature at either forward or reverse bias voltage is extensively studied by the filling of electrons in the e<sub>g</sub> and t<sub>2g</sub> band. The good rectifying behaviors, the magnetic tunable properties and the maximum magnetoresistance obtained at room temperature make this simple heterojunction promising for practical applications.
Cu<sub>2</sub>S thin films have been deposited on CdS/ITO (In<sub>2</sub>O<sub>3</sub>:Sn) substrates with various substrate temperatures by DC magnetron sputtering method. The effects of substrate temperature on the crystallization behavior and morphology are studied. Chemical composition of the films is confirmed by energy dispersive X-ray (EDX) spectroscopy. X-ray diffraction (XRD) analysis of the films reveals they have polycrystalline chalcocite structure with (110) texture. Field emission scanning electron microscopy (FESEM) show the crystalline nature of the films at higher substrate temperature, which is in accordance with XRD measurements. Stoichiometric analysis exhibits element composition with Cu/S concentrations ratio equal to 2 approximately.