About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
2025 Undergraduate Student Poster Contest
|
| Presentation Title |
SPU-13: Influence of Heterovalent Doping on Tetrahedral N Interstitial Formation inDilute GaAsN Alloys |
| Author(s) |
Matteo Carcassi, Joshua Cooper, Rachel S Goldman, Dashal Womack, Zhucong Xi, Liang Qi |
| On-Site Speaker (Planned) |
Matteo Carcassi |
| Abstract Scope |
Dilute alloying of GaAs with N enables bandgap tuning for near-infrared to mid-infrared optoelectronic devices. However, non-substitutional N incorporation has been linked to lower absorption and emission efficiencies in dilute-nitride-alloy-based devices, especially in those containing heterovalent dopants. In this work, we examine the influence of heterovalent dopants on N incorporation mechanisms in dilute GaAs1−xNx alloys with N composition intentionally below the threshold composition for formation of tetrahedral N interstitials (Ntetra) in undoped GaAs1−xNx. For undoped GaAs1−xNx, 20% of the N incorporates in non-substitutional sites, as (N-N)As and (N-As)As split interstitials. Interestingly, Si dopants induce the formation of Ntetra, while Be doping has a negligible effect on the interstitial type. Although elastic interactions due to opposite signs of the misfit volumes of Ntetra and NAs contribute to Ntetra incorporation above a threshold N composition, Fermi level stabilization of charged Ntetra by Si dopants reduces the threshold composition. |