Excitonic blue luminescence from p-LaCuOSen-InGa Zn5 O8 light-emitting diode at room temperature

Abstract

A hetero pn junction diode was fabricated by laminating an amorphous n -type InGa Zn5 O8 layer to a p -type LaCuOSe film epitaxially grown on a MgO (001) substrate. It exhibited a relatively sharp blue electroluminescence (EL) that peaked at ∼430 nm at room temperature when a forward bias voltage above 8 V was applied. The wavelength and bandwidth of the EL band agreed well with those of the excitonic photoluminescence band in LaCuOSe, which indicates that the EL band originates from the exciton in LaCuOSe. This experiment strongly suggests that layered compounds, LnCuOCh (Ln= lanthanide, Ch= chalcogen), are promising as the light-emitting layer in optoelectronic devices that operate in the blue-ultraviolet region. © 2005 American Institute of Physics.