Abstract
We employ first-principles density functional theory to investigate the electronic and structural properties of grain boundaries (GBs) in InAs. In particular, we study the energetics and passivation mechanisms of representative low-Sigma GBs, including Sigma 3(111), Sigma 3(112), Sigma 5(120), and Sigma 5(130), to establish their relative stability and experimental feasibility. We find that the symmetric-tilt twin-boundary Sigma 3(111) GB is the most stable GB, in excellent agreement with our experimentally characterized GB structures in InAs. In addition to our theoretically predicted GB structures, we systematically study and analyze different configurations of complex multifold experimentally observed InAs GB structures. We discuss the effect of different passivations and doping mechanisms on the electronic properties of the GBs. Understanding the exact nature of the GB electronic structure and stability, as well as their passivation mechanisms is a key step for the further development of InAs based optoelectronic devices on silicon and other heterogeneous large-area substrates.