Exploring the structure as well as electrical and photovoltaic mechanism in PrFe0.5Ni0.5O3/GaAs heterojunction

Structural and electrical transport study of PrFe0.5Ni0.5O3 heterojunction prepared by pulsed laser deposition (PLD) on GaAs (001) substrate is presented. The film deposited on this substrate is polycrystalline and has orthorhombic structure with space group Pbnm. The surface roughness was estimated around 3.4 nm and this increase in surface roughness results essentially from the grain formation. This heterojunction shows usual semiconducting behavior. Resistivity data have been fitted with variable range hopping (VRH) model, and small Polaron Hopping (SPH) model, from which different parameters like density of state at Fermi level N(Ef), hopping energy (Eh), hopping distance (Rh), and Mott׳s characteristic temperature (T0) were estimated. The photovoltaic behavior of this heterojunction was investigated via current–voltage (I–V) characteristics. A mechanism based on the well established model for photovoltaics in conventional semiconductors has been utilized to explain the observed trend in the present perovskite-type metal oxides. This observed behavior in the perovskite-type metal oxide may open a new window for its application in the modern optical based electronics.