Engineering the Interfacial Electronic: Structure of EpitaXial Gel/lAs(001) Heterointerfaces via Substitutional Boron Incorporation: The Roles of Doping and Interface Stoichiometry

A joint experimental and theoretical framework for the decoupling of boron (B) doping and stoichiometric-induced modifications to the structural properties and electronic band structure of germanium (Ge)/AlAs(001) heterostructures is presented. The effect of B -induced stress on nearest -neighbor Ge bonds is quantified via X-ray diffractometry and Raman spectroscopic analysis and subsequently interpreted through the lens of density functional perturbation theory. Similarly, experimental determination of the energy band alignment at the p -type Ge:B/AIAs heterointerface is understood using a density functional theory approach to model the influence of heterointerface stoichiometry and interatomic bonding between group IV and III V interfacial atoms on the valence and conduction band discontinuities. The modeled two monolayer interatomic diffusion at the Ge/AlAs heterointerface is confirmed via atom probe tomography analysis, demonstrating a 6 A interfacial width. These results present a unified picture of the Ge:B/AlAs(001) material system, highlighting the influence of B on its structural and electronic properties, and provide a path for the engineering of such heterointerfaces through high concentration dopant incorporation within the overlying Ge epilayer.