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  Weizman, M.; Scheller, L.-P.; Nickel, N.H.; Lips, K.; Yan, B.: Electron spin resonance in laser-crystallized polycrystalline silicon-germanium thin films. Physica Status Solidi A 207 (2010), p. 570-573

10.1002/pssa.200982897

Abstract:
The defect properties of laser-crystallized polycrystalline silicon–germanium (Si–Ge) thin films on glass substrates were investigated with electron spin resonance (ESR) and conductivity measurements. The ESR measurements reveal that lasercrystallized poly Si1
xGex thin films with 0<x<0.84 contain a dangling-bond concentration of about Ns¼41018 cm
3, roughly independent of the Ge content in this range. Surprisingly, the ESR signal vanishes completely for the Ge-rich alloys (x>0.84) and instead a broad atypical signal appears that we attribute to electric dipole induced spin resonance (EDSR). Samples that showed this behavior exhibited a nearly temperature- independent electrical conductivity for temperatures between 20 and 100 K. The data are discussed in terms of a model that is based on the formation of a defect band along the grain boundaries in the vicinity of the Fermi level.