Carrier dynamics in (Ga,In)(Sb,Bi)/GaSb quantum wells for laser applications in the mid-infrared spectral range

Abstract

We present experimental studies on low-temperature ($$T={4.2}\hbox { K}$$ T = 4.2 K ) carrier dynamics in (Ga,In)(Sb,Bi)/GaSb quantum wells (QWs) with the nominal In content of 3.7% and the Bi ranging from 6 to 8%. The photoreflectance experiment revealed the QW bandgap evolution with $$-{33}\pm {1}\hbox { meV}/\hbox {at}$$ - 33 ± 1 meV / at % Bi, which resulted in the bandgap tunability roughly between 629 and $${578}\hbox { meV}$$ 578 meV , setting up the photon emission wavelength between 1.97 and $${2.2}\,\upmu \hbox {m}$$ 2.2 μ m . The photoluminescence experiment showed a relatively small 3–10$$\hbox { meV}$$ meV Stokes shift regarding the fundamental QW absorption edge, indicating the exciton localisation beneath the QW mobility edge. The localised state’s distribution, being the origin of the PL, determined carrier dynamics in the QWs probed directly by the time-resolved photoluminescence and transient reflectivity. The intraband carrier relaxation time to the QW ground state, following the non-resonant excitation, occurred within 3–25$$\hbox { ps}$$ ps and was nearly independent of the Bi content. However, the interband relaxation showed a strong time dispersion across the PL emission band and ranging nearly between 150 and $${950}\hbox { ps}$$ 950 ps , indicating the carrier transfer among the localised state’s distribution. Furthermore, the estimated linear dispersion variation parameter significantly decreased from $$\Delta \tau \approx {20}$$ Δ τ ≈ 20 to $${10}\hbox { ps}/\hbox {meV}$$ 10 ps / meV with increasing the Bi content, manifested the increasing role of the non-radiative recombination processes with Bi in the QWs.

An advanced theoretical approach to study super-multiperiod superlattices: theory vs experiments

“…One of the main methods used for precise energy spectrum retrieving was PRS [19,20] . PRS is the non-contact, nondestructive, and highly sensitive express method for diagnosing nanostructures.…”

Influence of the Bismuth Content on the Optical Properties and Photoluminescence Decay Time in GaSbBi Films

“…However, so far, most studies have focused on the growth and structural properties of the novel alloy, with only a few groups demonstrating in detail their optical properties. Recently, some attention has also been paid to the investigation of the carrier dynamics in GaInSbBi/GaSb quantum wells . In this study, we focus on the investigation of the photoluminescence (PL) lifetime in bulk crystal GaSbBi layers.…”

“…Recently, some attention has also been paid to the investigation of the carrier dynamics in GaInSbBi/GaSb quantum wells. 12 In this study, we focus on the investigation of the photoluminescence (PL) lifetime in bulk crystal GaSbBi layers. The results of this work may prove valuable for further development of mid-infrared mode-lock lasers, where the cavity round-trip parameter is crucial for its operation.…”