Cascaded active regions in 2.4μm GaInAsSb light-emitting diodes for improved current efficiency

Abstract

By cascading multiple GaInAsSb active regions, the authors have fabricated 2.4μm light-emitting diodes that, for a given light output, operate at reduced current and higher voltage, which can be advantageous for battery-powered sensor applications. Tunnel heterojunctions separating emission regions add no measurable series resistance. Devices are demonstrated at room temperature with continuous wave output.

High power continuous-wave GaSb-based superluminescent diodes as gain chips for widely tunable laser spectroscopy in the 1.95–2.45 μm wavelength range

“…Measured SLDs exhibited very high CW maximum output powers at RT of 40 mW at 2.05 lm, 10 mW at 2.25 lm, and 5 mW at 2.4 lm. The latter results are at least by an order of magnitude better than current state-of-the-art, 7,12 where output of 1 mW in pulsed operation 7 and 0.35 mW in CW 12 at 2.4 lm has been demonstrated. We attribute such increase in performance to the superior quality of our epitaxially grown layers and, thus, better gain material.…”

Broadband 2.4μm superluminescent GaInAsSb/AlGaAsSb quantum well diodes for optical sensing of biomolecules

“…The thicker emission regions allow mesa diodes to operate at lower current densities, reducing the impact of Auger scattering, while SLDs use quantum wells which operate at higher current densities, but are engineered to have lower Auger coefficients. On the other hand, if we compare maximum radiances (power/area/solid angle), mesa diodes do much worse: about 1 W/cm 2 /sr for mesa diodes in Refs [5,6] compared to 38 kW/cm 2 /sr for edge emitting SLDs, a five order of magnitude difference. The much higher radiance of SLDs is due to the very small surface area of an edge emitting SLD compared to a the larger emission area of a surface emitting mesa diode, and may be of use for coupling the output power to small apertures of waveguides and fiber optics.…”

“…Emission spectra were measured using a Nicollet 560 FTIR spectrometer using a double signal modulation approach in combination with an LN 2 cooled InSb detector. 5 …”

Light-Emitting Diodes Operating at 2 $\mu{\rm m}$ With 10 mW Optical Power

“…Thus, an internal quantum efficiency of more than 100% can be achieved. Cascading injection also permits the LED operating voltage to be increased permitting impedance matching between the LED and the driving electronics [3]. Manuscript In this letter, we report on GaSb based λ∼2 μm LEDs generating more than 10 mW of quasi-continuous wave (qCW) optical power at room temperature.…”

“…Bipolar cascading design has been demonstrated as an effective way to stack several active regions within a single device [3]- [5]. Among the advantages of active region cascading are electron recycling and operating voltage conversion.…”