Low cost inorganic white light emitting diode based on submicron ZnO rod arrays and electrodeposited Cu2O thin film

We present here the fabrication and characterization of low cost inorganic white light emitting diode (LED) based on submicron ZnO rod arrays and Cu2O thin film. Firstly, n-ZnO rod arrays were grown on FTO substrate by hydrothermal method at 150 °C. Then, p-Cu2O thin film was electrodeposited on top of ZnO arrays from alkaline cupric lactate solution at 60 °C. X-ray diffraction and scanning electron microscopy were employed to investigate the structural and the morphology of the prepared samples as well as the diode device. The results indicate the formation of hexagonal structure of ZnO arrays and cubic structure of polycrystalline Cu2O thin film. The performance of LED device was investigated employing I-V and electroluminescence measurements. The heterojunction device showed good rectification behavior and a broad emission covering visible spectrum for all applied voltage which indicates the white electroluminescence of the heterostructure device. Therefore, the inorganic ZnO arrays/Cu2O thin film is a promising heterojuniction for low cost and large-scale production of white LED.