Determination of the Strain Influence on the InAs/InAsSb Type-II Superlattice Effective Masses

Area of Science:

• Materials Science
• Condensed Matter Physics
• Optoelectronics

Background:

• A³B⁵ materials are vital for fabricating superlattices (SLs) used in infrared (IR) detection devices.
• These IR detectors find applications in military, industrial, and medical fields.

Purpose of the Study:

• To theoretically assess the impact of strain on the bandgap energy and effective masses of electrons and holes in InAs/InAsSb type-II superlattices (T2SLs).
• To analyze the strain effects at 150 K for optimizing device performance.

Main Methods:

• Utilized the commercial SimuApsys program for theoretical simulations.
• Employed the k·p method for T2SL modeling, assessing Luttinger coefficients with Kane coefficient F=0.
• Determined ternary material bandgap energy using a bowing parameter (b_g) of 750 meV at 150 K.
• Estimated cutoff wavelengths from absorption coefficients and calculated bandgap energy using E_g = 1.24/λ_cutoff.

Main Results:

• Strain in T2SLs was shown to shift the bandgap energy (E_g).
• Strain also affects the effective masses of electrons (m_e) and holes (m_h).
• Simulated results at 150 K demonstrated good agreement with experimental measurements.

Conclusions:

• Strain is a critical factor influencing the optical and electrical properties of T2SLs.
• The study provides theoretical insights into strain engineering for advanced IR detector design.
• The findings are relevant for developing high-performance infrared detection technologies.