Synthesis and characterization of ZnO micro-rods and temperature-dependent characterizations of heterojunction of ZnO microrods/CdTe and ZnO microrods/ZnTe structures

ZnO microrods were fabricated on ZnO-coated SnO2 glass substrates by spray pyrolysis method. To obtain p-n heterojunction, p type CdTe and ZnTe layers were deposited on ZnO microrods. The structural characterizations demonstrated that ZnO microrods have a hexagonal wurtzite structure with vertically aligned rod morphology. Additionally, hexagonal rod geometry was compressed by coating CdTe layer on micro-sized ZnO rods. The diode type rectifying behaviour of ZnO microrods/CdTe and ZnO microrods/ZnTe heterojunctions have been carried out and the electrical characteristics of both devices have been analyzed with current-voltage measurements as a function of temperature. Although the mismatch between ZnO and ZnTe, the ZnO microrods/ZnTe heterojunction showed good rectifying behaviour at all temperatures. According to the our findings, both ideality factor n and barrier heightΦb are temperature-dependent due to the deviation from pure thermionic emission theory and inhomogeneity at the interface of ZnO-CdTe and ZnO-ZnTe.