Towards Large-Area Black Phosphorous Midwave-IR Optoelectronics

High-efficiency mid-wavelength infrared (mid-IR, 3–5 µm) optoelectronics, including light emitting diodes (LEDs) and photodetectors, are of high demand for emerging applications in spectroscopy, imaging, and gas sensing. Black phosphorus (bP) has emerged as a unique optoelectronic material for mid-IR applications with performances surpassing those of conventional III-V and II-VI semiconductors of similar bandgap. In this talk, I will present recent advancements on understanding and controlling the radiative and non-radiative recombination rates as a function of bP thickness. We observe higher photoluminescence quantum yields in bP as compared to conventional III-V and II-VI semiconductors of similar bandgaps due to the smaller Auger recombination rate. As a result, bP mid-IR LEDs with external quantum efficiency of >4% are reported, outperforming the state-of-the-art in this wavelength range. Furthermore, device encapsulation and packaging technologies are explored with extrapolated half lifetime of ~15,000 hours based on accelerated lifetime measurements. Finally, I will present strategies for large-area device fabrication and processing.