The n-type Ge photodetectors with gold nanoparticles deposited to enhance the responsivity

• Published in: Nanoscale research letters 2014-11, Vol.9 (1), p.640-640, Article 640
• Main Authors: Hsiao, Hao-Tse, Ni, I-Chih, Tzeng, Shien-Der, Lin, Wei-Fan, Lin, Chu-Hsuan
• Format: Article
• Language: English
• Subjects: 2014 International Symposium on Next-Generation Electronics (ISNE 2014); Chemistry and Materials Science; Materials Science; Molecular Medicine; Nano Express; Nanochemistry; Nanoscale Science and Technology; Nanotechnology; Nanotechnology and Microengineering
• ISSN: 1931-7573; 1556-276X; 1556-276X
• DOI: 10.1186/1556-276X-9-640

Gold nanoparticles (AuNPs) have been deposited on n-type Ge photodetectors to improve the responsivity. Two different coverage ratios, including 10.5 and 30.3% of AuNPs have been prepared, and the fabricated photodetectors are compared with the control sample. The 1,310-nm responsivities at -2 V of the control, 10.5% AuNPs, and 30.3% AuNPs samples are 465, 556, and 623 mA/W, respectively. The AuNPs could increase the responsivities due to the plasmon resonance. The reflectance spectra of these samples have been measured to verify that plasmon resonance contributes to the forward scattering of incident light. The reflectance decreases with AuNP deposition, and a denser coverage results in a smaller reflectance. The smaller reflectance indicates more light could penetrate into the Ge active layer, and it results in a larger responsivity.