Johnson Sean, Pokharel Rabin, Lowe Michael, Kuchoor Hirandeep, Nalamati Surya, Davis Klinton, Rathnayake Hemali, Iyer Shanthi
Department of Electrical and Computer Engineering, North Carolina A&T State University, Greensboro, NC, 27411, USA.
Nanoengineering, Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro, NC, 27401, USA.
Sci Rep. 2021 Feb 25;11(1):4651. doi: 10.1038/s41598-021-83973-9.
This study presents the first report on patterned nanowires (NWs) of dilute nitride GaAsSbN on p-Si (111) substrates by self-catalyzed plasma-assisted molecular beam epitaxy. Patterned NW array with GaAsSbN of Sb composition of 3% as a stem provided the best yield of vertical NWs. Large bandgap tuning of ~ 75 meV, as ascertained from 4 K photoluminescence (PL), over a pitch length variation of 200-1200 nm has been demonstrated. Pitch-dependent axial and radial growth rates show a logistic sigmoidal growth trend different from those commonly observed in other patterned non-nitride III-V NWs. The sigmoidal fitting provides further insight into the PL spectral shift arising from differences in Sb and N incorporation from pitch induced variation in secondary fluxes. Results indicate that sigmoidal fitting can be a potent tool for designing patterned NW arrays of optimal pitch length for dilute nitrides and other highly mismatched alloys and heterostructures.
本研究首次报道了通过自催化等离子体辅助分子束外延在p-Si(111)衬底上制备稀氮化物GaAsSbN的图案化纳米线(NWs)。以Sb组成为3%的GaAsSbN作为主干的图案化NW阵列提供了垂直NWs的最佳产率。通过4K光致发光(PL)确定，在200-1200nm的节距长度变化范围内，实现了约75meV的大带隙调谐。节距依赖的轴向和径向生长速率呈现出逻辑S形生长趋势，这与在其他图案化非氮化物III-V族NWs中通常观察到的不同。S形拟合进一步深入了解了由于节距引起的二次通量变化导致的Sb和N掺入差异所引起的PL光谱位移。结果表明，S形拟合可以成为设计稀氮化物以及其他高度失配合金和异质结构的最佳节距长度的图案化NW阵列的有力工具。
