Abstract

We demonstrate that coupled AlGaN/GaN quantum wells with asymmetric widths (L₁ − L₂ < 30 Å) achieve up to 4.5× higher mobility than single wells at optimal separation (d = 100 Å). Crucially, mobility surpasses single wells when d > 40 Å reversing the trend at smaller distances. This enhancement stems from double-layer screening that suppresses remote/background impurities and dislocations, while LO phonon scattering remains unaffected. For identical wells, coupled systems underperform single wells at d < 40 Å but exceed them beyond this threshold. Peak gains occur at cryogenic temperatures (77 K). Our results provide a robust theoretical framework to optimize mobility in AlGaN/GaN heterostructures, reducing experimental trial-and-error in quantum device engineering.

Abstract

We demonstrate that coupled AlGaN/GaN quantum wells with asymmetric widths (L₁ − L₂ < 30 Å) achieve up to 4.5× higher mobility than single wells at optimal separation (d = 100 Å). Crucially, mobility surpasses single wells when d > 40 Å reversing the trend at smaller distances. This enhancement stems from double-layer screening that suppresses remote/background impurities and dislocations, while LO phonon scattering remains unaffected. For identical wells, coupled systems underperform single wells at d < 40 Å but exceed them beyond this threshold. Peak gains occur at cryogenic temperatures (77 K). Our results provide a robust theoretical framework to optimize mobility in AlGaN/GaN heterostructures, reducing experimental trial-and-error in quantum device engineering.

Abstract

We demonstrate that coupled AlGaN/GaN quantum wells with asymmetric widths (L₁ − L₂ < 30 Å) achieve up to 4.5× higher mobility than single wells at optimal separation (d = 100 Å). Crucially, mobility surpasses single wells when d > 40 Å reversing the trend at smaller distances. This enhancement stems from double-layer screening that suppresses remote/background impurities and dislocations, while LO phonon scattering remains unaffected. For identical wells, coupled systems underperform single wells at d < 40 Å but exceed them beyond this threshold. Peak gains occur at cryogenic temperatures (77 K). Our results provide a robust theoretical framework to optimize mobility in AlGaN/GaN heterostructures, reducing experimental trial-and-error in quantum device engineering.

Abstract

We demonstrate that coupled AlGaN/GaN quantum wells with asymmetric widths (L₁ − L₂ < 30 Å) achieve up to 4.5× higher mobility than single wells at optimal separation (d = 100 Å). Crucially, mobility surpasses single wells when d > 40 Å reversing the trend at smaller distances. This enhancement stems from double-layer screening that suppresses remote/background impurities and dislocations, while LO phonon scattering remains unaffected. For identical wells, coupled systems underperform single wells at d < 40 Å but exceed them beyond this threshold. Peak gains occur at cryogenic temperatures (77 K). Our results provide a robust theoretical framework to optimize mobility in AlGaN/GaN heterostructures, reducing experimental trial-and-error in quantum device engineering.