Mid-infrared LEDs based on lattice-mismatched hybrid IV-VI/III-V heterojunctions

TL;DR

This paper demonstrates mid-infrared LEDs using hybrid IV-VI/III-V heterojunctions, leveraging low Auger recombination in IV-VI semiconductors to achieve room-temperature emission with practical power and efficiency levels.

Contribution

It introduces a novel hybrid heterojunction approach combining IV-VI and III-V semiconductors for efficient mid-IR LEDs at room temperature.

Findings

Electrically injected PbSe/III-V LEDs emit at 3.8 μm with 400 μW power.

GeSe/PbSnSe/GaAs LEDs emit at 5 μm with 45 μW power.

Devices operate despite high threading dislocation densities.

Abstract

Light-emitting diodes (LEDs) can bridge the gap between narrow linewidth, expensive lasers and broadband, inefficient thermal globars for low-cost chemical sensing in the mid-infrared (mid-IR). However, the efficiency of III-V based mid-IR LEDs at room temperature is low, primarily limited by strong nonradiative Auger-Meitner recombination that is only partially overcome with complex quantum-engineered active regions. Here, we exploit the intrinsically low Auger Meitner recombination rates of the IV-VI semiconductors PbSe and PbSnSe, while leveraging the mature III-V platform through the fabrication of hybrid heterojunctions that mediate the ~8% lattice mismatch to GaAs. Electrically injected n-PbSe/p-GaAs LEDs emit at 3.8 um with output powers up to 400 uW under pulsed operation and a peak wall plug efficiency of 0.08% at room temperature, approaching the performance of commercial III-V LEDs at similar wavelengths. Incorporating 7% Sn extends the emission to 5 um in GeSe/PbSnSe/GaAs LEDs with output powers up to 45 uW. Notably, both devices operate despite threading dislocation densities on the order of 1e9/cm^2, underscoring the potential of hybrid IV-VI/III-V heterojunction architectures. We show that combining the complementary advantages of IV-VI and III-V semiconductors offers a simple and efficient mid IR optoelectronic platform for a rapidly expanding set of applications.