INGAN LASER-DIODE GROWN ON 6H-SIC SUBSTRATE USING LOW-PRESSURE METALORGANIC VAPOR-PHASE EPITAXY

InGaN multiple quantum well (MQW) laser diodes were fabricated on a 6H -SiC substrate using low-pressure metalorganic vapor phase epitaxy (LP -MOVPE). Both threshold current and slope efficiency were improved by changing the MQW structure from five 2.5 nm wells to three 4 nm wells. The anomalously large improvement in slope efficiency suggested the p resence of inhomogeneous hole injection. The use of high-reflection (W R) coating also reduced the threshold current. A threshold current of 500 mA was obtained as the minimum value under pulsed current injectio n at room temperature, corresponding to a threshold current density of 13 kA/cm(2). The maximum pulse duration of 1.5 mu s was obtained unde r 1 kHz repetition frequency. The number of lasing emission lines incr eased as the current increased above the threshold. (C) 1998 Elsevier Science B.V. All rights reserved.