摘要： P-N junction diodes with excellent rectifying characteristics were prepared by segregating the Ge nanocrystals of Si1−xGex thin films deposited by co-sputtering. The current-voltage characteristics in darkness and under illumination were studied. The correlation between the p-n junction performance and the microstructure of the films is discussed, and the rectifying property became stronger as the fraction of Ge in the Si1−xGex films increased. The optical bandgap can be tuned by controlling the grain size in Ge and SiGe nanocrystals. The graded structure of the Si1−xGex photodiode is proposed to widen the light absorption region. The concept can be used to design high-efficiency photodiodes. •Photodiodes with nanocrystalline SiGe were deposited by co-sputtering method.•High Ge content yielded good crystallinity and the optical-electrical property.•Graded SiGe films is the novel photodiode due to excellent light absorption. 出版者： Elsevier B.V 出版日期： 2016-12-01 出處： Materials letters, 2016-12, Vol.184, p.308-311 資源來源： Elsevier ScienceDirect Journals Complete 版權： 2016 Elsevier B.V. 識別號： ISSN: 0167-577X 識別號： EISSN: 1873-4979 識別號： DOI: 10.1016/j.matlet.2016.08.054
