Ge nanoparticles in SiO2 for near infrared photodetectors with high performance.
Sci Rep
; 9(1): 10286, 2019 Jul 16.
Article
em En
| MEDLINE
| ID: mdl-31312003
ABSTRACT
In this work we prepared films of amorphous germanium nanoparticles embedded in SiO2 deposited by magnetron sputtering on Si and quartz heated substrates at 300, 400 and 500 °C. Structure, morphology, optical, electrical and photoconduction properties of all films were investigated. The Ge concentration in the depth of the films is strongly dependent on the deposition temperature. In the films deposited at 300 °C, the Ge content is constant in the depth, while films deposited at 500 °C show a significant decrease of Ge content from interface of the film with substrate towards the film free surface. From the absorption curves we obtained the Ge band gap of 1.39 eV for 300 °C deposited films and 1.44 eV for the films deposited at 500 °C. The photocurrents are higher with more than one order of magnitude than the dark ones. The photocurrent spectra present different cutoff wavelengths depending on the deposition temperature, i.e. 1325 nm for 300 °C and 1267 nm for 500 °C. These films present good responsivities of 2.42 AW-1 (52 µW incident power) at 300 °C and 0.69 AW-1 (57 mW) at 500 °C and high internal quantum efficiency of â¼445% for 300 °C and â¼118% for 500 °C.
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MEDLINE
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En
Ano de publicação:
2019
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Article