Enhancement of the Si p-n diode NIR photoresponse by embedding β-FeSi2 nanocrystallites


Галкин К. Н., Галкин Н. Г., Горошко Д. Л., Чусовитин Е. А., Шевлягин А. В., А.К. Гутаковский

Scientific Reports, Q1

Статьи в журналах

Scientific Reports

UK, London, Nature Research

Scientific Reports, 5, 14795 (2015)

14795-1 - 14795-9



Shevlyagin A. V. et al. Enhancement of the Si pn diode NIR photoresponse by embedding β-FeSi 2 nanocrystallites //Scientific reports. – 2015. – Т. 5. – №. 1. – С. 1-9.

By using solid phase epitaxy of thin Fe films and molecular beam epitaxy of Si, a p+-Si/p-Si/β-FeSi2 nanocrystallites/n-Si(111) diode structure was fabricated. Transmission electron microscopy data confirmed a well-defined multilayered structure with embedded nanocrystallites of two typical sizes: 3–4 and 15–20 nm and almost coherent epitaxy of the nanocrystallites with the Si matrix. The diode at zero bias conditions exhibited a current responsivity of 1.7 mA/W, an external quantum efficiency of about 0.2% and a specific detectivity of 1.2 × 109 cm × Hz1/2/W at a wavelength of 1300 nm at room temperature. In the avalanche mode, the responsivity reached up to 20 mA/W (2% in terms of efficiency) with a value of avalanche gain equal to 5. The data obtained indicate that embedding of β-FeSi2 nanocrystallites into the depletion region of the Si p-n junction results in expansion of the spectral sensitivity up to 1600 nm and an increase of the photoresponse by more than two orders of magnitude in comparison with a conventional Si p-n junction. Thereby, fabricated structure combines advantage of the silicon photodiode functionality and simplicity with near infrared light detection capability of β-FeSi2.