Inhibiting strain-induced surface roughening: dislocation-free Ge/Si and Ge/SiGe core-shell nanowires.
Elastic strain is a critical factor in engineering the electronic behavior of core-shell semiconductor nanowires and provides the driving force for undesirable surface roughening and defect formation. We demonstrate two independent strategies, chlorine surface passivation and growth of nanowires with low-energy sidewall facets, to avoid strain-induced surface roughening that promotes dislocation nucleation in group IV core-shell nanowires. Metastably strained, dislocation-free, core-shell nanowires are obtained, and axial strains are measured and compared to elasticity model predictions.
Materials Science and Engineering and Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA. oldthorpe@stanford.edu
Irene A
IA
Goldthorpe
Ann F
AF
Marshall
Paul C
PC
McIntyre