摘要： •Amorphous Si1−xGex films were prepared by co-sputtering by using rapid thermal annealing to form nanocrystal films.•Si–Ge alloy does not form total solid solution that is shown in phase diagram.•HRTEM images indicated that Ge atoms segregated and formed Ge clusters that are embedded in the amorphous Si–Ge matrix.•Ge segregation permitted high mobility; the grain size increased and the resistivity decreased with higher Ge content.•The rectifying property became stronger with the Ge fraction in the Si1−xGex diodes. Si1−xGex diodes are used as photodetectors, which provide a greater output current under illumination. Amorphous Si1−xGex films were prepared by co-sputtering on an oxidized Si wafer, followed by rapid thermal annealing to form nanocrystal films. The formation of Ge nanocrystals was not at thermodynamic equilibrium formed in the amorphous Si1−xGex matrix. High-resolution transmission electron microscopy was used to characterize the increase in the size of the grains in the Ge nanocrystals as the Ge content increased. The Ge nanocrystals have a greater absorption in the near-infrared region and higher carrier mobility than SiGe crystals, and the variation in their grain sizes can be used to tune the bandgap. This characteristic was exploited herein to fabricate n-Si1−xGex/p-Si1−xGex p–n diodes on insulating substrates, which were then examined by analyzing their current–voltage characteristics. The rectifying property became stronger as the fraction of Ge in the Si1−xGex films increased. The Si1−xGex diodes are utilized as photodetectors that have a large output current under illumination. This paper elucidates the correlations between the structural, optical and electrical properties and the p–n junction performance of the film. 出版者： Elsevier B.V 出版日期： 2015-09-15 出處： Applied surface science, 2015-09, Vol.349, p.387-392 版權： 2015 Elsevier B.V. 識別號： ISSN: 0169-4332 識別號： EISSN: 1873-5584 識別號： DOI: 10.1016/j.apsusc.2015.05.034
