InGaAs resonant cavity light emitting diodes (RC LEDs)

We have developed resonant-cavity light emitting diodes (RC LED) with very good emission charactristics. RC LEDs proved to be more tolerant to the epitaxial growth parameters and device fabrication procedures. As relatively robust devices they are less sensitive to typical for VCSEL manufacturing challenges and seem to have great potential for applications. Comparing to classical LED the spectrum of RC LED is concentrated into a narrow line with less than 2 nm halfwidth. The RC LED spectrum is determined mainly by the cavity resonance; its width decreases with the increase of the cavity finesse and the intensity increase reflect the on axis cavity enhancement. Additional, favorable RC LED property is its emission characteristic directionality which depends on the tuning between QW emission and cavity resonance. We have optimized the series resistance of diodes. The best result have been obtained for digital alloy graded distributed Bragg reflector (DBR) interfaces. The MBE grown structures were tested extensively prior to the device fabrication. by reflectivity and photoluminescence. The assembled diodes were subjected to electrical and optical tests. Generally we have found very good correlation between the results of optical tests (PL maps) on as grown wafers and probe tests on final devices.