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.
Goldthorpe
Irene A
IA
Materials Science and Engineering and Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA. oldthorpe@stanford.edu
Marshall
Ann F
AF
McIntyre
Paul C
PC