Semiconductor La0.67Sr0.33CoO3 thin films has been investigated as function of oxygen atmosphere during film growth in pulsed laser deposition. While amount of oxygen greatly depends on an oxygen atmosphere during film growth, in condition of oxygen atmosphere from 4 Pa to 100 Pa, the carrier in La0.67Sr0.33CoO3 thin films were found to be positive, exhibiting p-type conduction. Furthermore, we prepared (p)-La0.67Sr0.33CoO3/(i)-CeO2/(n)-InGaZnOx heterostructure devices and investigated electrical properties. These results showed rectifying behavior was clearly observed in heterostructure at room temperature. The sharp increase of current with voltage, when voltage exceeds diffusion potential, indicates the conductive resistance was small. p-type semiconductor La0.67Sr0.33CoO3 thin films and their p-n heterostructure devices with rectifying behavior may aid in the development of various semiconductor devices such as three terminal transistors, light emitted diode (LED) and solar cell. (C) 2017 Elsevier B.V. All rights reserved.