Infrared and visible emission from electroluminescent device based on GaN:Er

We investigated the photoluminescence (PL) and electroluminescence (EL) properties of a GaN:Er based device. It was found that 1.54 µm PL spectra obtained with above- and below-band-gap excitation and the EL spectrum are similar. Green and infrared EL were observed at room temperature in the vicinity of the negatively biased contact. The voltage dependence of the EL intensity shows voltage thresholds of 12.5 V and 5 V for the green and infrared emissions respectively. The excitation mechanism seems to be the impact excitation of Er3+ ions by hot electrons, which are injected and accelerated by the electric field. However, above the voltage thresholds both emissions exhibit different dependencies on the applied voltage, indicating that the excitation mechanisms for both emissions are different. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)