TRPL lifetime measurement of InGa0.2AsSb0.27 alloys lattice-matched to GaSb

What is it about?

This study presents the molecular beam epitaxy (MBE) growth of the indium-rich InGaAsSb alloy with a 0.26 eV bandgap, lattice-matched (LM) to GaSb. A significant finding is the high material metrics, particularly the minority carrier lifetime (0.3 μs) and the background carrier concentration (8 × 10¹⁵ cm⁻³), which product reaches half the value of the reference InAsSb alloy LM to GaSb. This indicates the suitability of indium-rich InGaAsSb alloys for low-dark-current, high-quantum-efficiency mid-wave infrared optoelectronic detectors with spectral responsivity extending up to 5 µm.

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Why is it important?

Structural, optical and carrier recombination properties of In 0.8 GaAsSb 0.27 alloys grown lattice-matched to GaSb are reported. Strong fundamental absorption of alloys implies its suitability for use as an active region of optoelectronic devices, high quantum efficiency detectors for the entire mid-wave infrared (MWIR) wavelength range. Use of bulk absorber for the active region can address the lower absorption of InAsSb/InAs strained layer superlattices currently dominating high-performance MWIR sensors. The visibility of the realization of the diffusion current dominated by radiative recombination at T=77K in indium-rich InGaAsSb alloys has been demonstrated, which suggests the realization of low dark current detectors. To the best of our knowledge, there is only one report on the growth of indium-rich InGaAsSb alloys lattice-matched to GaSb. In this work significantly lower low-temperature PL width of the alloys with similar composition was demonstrated, which encourages the use of the alloys