ИАПУ ДВО РАН

Stress-induced indirect to direct band gap transition in β-FeSi2 nanocrystals embedded in Si


2017

Балаган С. А., Галкин К. Н., Галкин Н. Г., Горошко Д. Л., Доценко С. А., Чусовитин Е. А., Шевлягин А. В., TS Shamirzaev, AK Gutakovskii, M Iinuma, Y Terai

Тезисы

AIP Conference Proceedings

USA, Maryland, AIP Publishing

AIP Conference Proceedings 1874, 030007 (2017)

5

978-0-7354-1554-6

Shevlyagin A. V. et al. Stress-induced indirect to direct band gap transition in β-FeSi2 nanocrystals embedded in Si //AIP Conference Proceedings. – AIP Publishing LLC, 2017. – Т. 1874. – №. 1. – С. 030007.

Embedded in silicon β-FeSi2 nanocrystals (NCs) were grown on Si(111) by solid phase epitaxy of a thin iron film followed by Si molecular beam epitaxy. After solid phase epitaxy, a mixture of β-FeSi2 and ε-FeSi nanocrystals is formed on the surface, sometimes β and ε phases coexist inside one nanocrystal. During initial stage of Si molecular beam epitaxy all ε-FeSi transforms into β-FeSi2. β-FeSi2 nanocrystals tend to move following Si growth front. By adjusting growth condition, we manage to prevent the nanocrystals from moving and to fabricate 7-layer n-Si(111)/β-FeSi2_NCs/p+-Si silicon heterostructure with embedded β-FeSi2 NCs. An epitaxial relationship and a stress induced in the nanocrystals by silicon matrix were found to be suitable for indirect to direct band gap transition in β-FeSi2. Of the heterostructure, a n-i-p avalanche photodetector and a light-emitting diode were formed. They have shown relatively good performance: ultrabroadband photoresponse from the visible (400 nm) to short-wavelength infrared (1800 nm) ranges owing to quantum-confined Stark effect in the nanocrystals and optical emission power of up to 25 µW at 9 A/cm2 with an external quantum efficiency of 0.009% at room temperature owing to a direct fundamental transition in stressed β-FeSi2 nanocrystals.

https://doi.org/10.1063/1.4998036

https://aip.scitation.org/doi/abs/10.1063/1.4998036