Bandgap Engineering of GaAs, InAs, and InSb Quantum Dots for Narrow-Bandgap Devices

This study investigates the bandgap engineering of GaAs, InAs, and InSb quantum dots (QDs) for narrow-bandgap device applications using the Effective Mass Approximation (EMA) model. It analyzes how quantum confinement modifies the bandgap as the QD radius varies from the strong confinement regime (1–2 nm) to the weak confinement regime (6–8 nm). The results show a pronounced increase in bandgap energy with decreasing radius, driven by enhanced carrier confinement and stronger electron–hole localization at the nanoscale. Among the three materials, InSb QDs exhibit the smallest bandgaps, highlighting their potential for infrared photodetectors and long-wavelength optoelectronic systems. InAs QDs display intermediate bandgap values, making them suitable for near-infrared detection and high-efficiency photovoltaic devices. GaAs QDs maintain the largest bandgaps over the same size range, supporting applications in visible to near-infrared emitters and sensors. Overall, the findings demonstrate that precise size control enables effective bandgap tuning in III–V semiconductor QDs and confirm that the EMA model provides a reliable framework for predicting their size-dependent electronic properties.