High-Performance Mid-Wavelength InAs/GaSb Superlattice Infrared Detectors Grown by Production-Scale Metalorganic Chemical Vapor Deposition
We demonstrate high-performance mid-wavelength <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula>-<inline-formula> <tex-math notation="LaTeX">$i$ </tex-math></inline-formula>-<inline-formula> <tex-math notation="LaTeX">$n$ </tex-math></inline-formula> infrared detectors based on InAs/GaSb type-II superlattices (SLs) grown by a production-scale metalorganic chemical vapor deposition system. Through a specially-designed gas switching sequence and the use of GaAs-type of interfacial layers, strain-balanced SLs with excellent material quality were obtained, as evidenced by atomic force microscopy, photoluminescence, X-ray diffraction, and transmission electron microscopy. The processed devices, with a cutoff wavelength around 4.8 <inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula>, exhibited a R<sub>0</sub>A of <inline-formula> <tex-math notation="LaTeX">$2.3\times 10^{4}~\Omega $ </tex-math></inline-formula>cm<sup>2</sup> and a peak responsivity of 1.4 A/W at 77 K. A specific detectivity of <inline-formula> <tex-math notation="LaTeX">$7.2\times 10^{12}$ </tex-math></inline-formula> cmHz<inline-formula> <tex-math notation="LaTeX">$^{1/2}$ </tex-math></inline-formula>/W was achieved at <inline-formula> <tex-math notation="LaTeX">$3.7~\mu \text{m}$ </tex-math></inline-formula>. These values are comparable with those reported for InAs/GaSb SL detectors with similar cutoff wavelengths grown by molecular beam epitaxy.