AlGaN-based ultraviolet light-emitting diodes on sputter-deposited A1N templates with epitaxial AlN/AlGaN superlattices

摘要

AbstractWe demonstrate AlGaN-based ultraviolet light-emitting diodes (UV-LEDs) grown by metalorganic chemical vapor deposition (MOCVD) on sputter-deposited AlN templates upon sapphire substrates. An AlN/AlGaN superlattices structure is inserted as a dislocation filter between the LED structure and the AlN template. The full width at half maximum values for (0002) and (101¯2) X-ray rocking curves of the n-type Al0.56Ga0.44N layer are 513 and 1205 arcsec, respectively, with the surface roughness of 0.52 nm. The electron concentration and mobility measured by Hall measurement are 9.3 × 1017cm−3and 54 cm2/V·s at room temperature, respectively. The light output power of a 282-nm LED reaches 0.28 mW at 20 mA with an external quantum efficiency of 0.32%. And the values of leakage current and forward voltage of the LEDs are ∼3 nA at −10 V and 6.9 V at 20 mA, respectively, showing good electrical performance. It is expected that the cost of the UV-LED can be reduced by using sputter-deposited AlN template.Highlights•AlGaN-based UV-LEDs on sputtered AlN templates are realized, without commonly used MOCVD-grown AlN templates.•With the use of the sputtered AlN template, the cost of the UV-LEDs could be reduced.•The 200 nm AlN template is proved to be better to improve the epitaxial crystal quality and performance of the UV-LED.