Indium-free violet LEDs grown by HVPE

We report on first demonstration of violet light emitting diodes (LED) based on AlGaN/GaN/AlGaN heterostructures grown by hydride vapor phase epitaxy (HVPE). The unique aspects of this technological approach are (i) growth of Al-containing epitaxial material by HVPE and (ii) use of HVPE to fabricate submicron multi-layer epitaxial structures. The LEDs provide light emission at the wavelength of 415–420 nm that did not shift with forward current. External efficiency up to 2.5% is reached at the current of 20 mA. The brightness of LED lamp is as high as 400–500 mcd. This suggests HVPE as an alternative technique for growing AlGaN-based LED structures. Results of the LED modeling and characterization are discussed. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)