Influence of strain on growth mode and electro-optical properties of high-brightness InGaN-LEDs on SiC

We present a detailed study, on the influence of buffer strain on the MOVPE crystal growth mode in the QW active layer of high-brightness InGaN LEDs o n SiC substrate. While highly strained buffers are related to InGaN QWs wit h homogeneous In-distribution, low In-concentration and reduced quantum eff iciency, buffers with reduced strain are shown to induce InGaN-QW growth wi th a dot-like In-distribution, locally high In-concentration and good quant um efficiency. Using an optimised buffer technology, we developed extremely bright InGaN QW-LEDs with a brightness of more than 7 mW (at 460 nm and 20 mA) in a 5 mm radial lamp, good wavelength stability, low forward voltage, high ESD-stability and low ageing. (C) 2001 Elsevier Science B.V. All righ ts reserved.