TY - JOUR
T1 - Extending the near-infrared band-edge absorption spectrum of silicon by proximity to a 2D semiconductor
AU - Apicella, Valerio
AU - Fasasi, Teslim Ayinde
AU - Wong, Hon Fai
AU - Leung, Dennis C.W.
AU - Ruotolo, Antonio
N1 - Funding Information:
The work described in this paper was partially supported by a grant from Florida Polytechnic University (Grant No. GR-2000026 ).
Publisher Copyright:
© 2020
PY - 2021/2/1
Y1 - 2021/2/1
N2 - Because of its low-cost, silicon is the standard material for photovoltaic conversion. Yet, its band-edge absorption spectrum is narrower than the spectrum of the solar radiation, which reduces its conversion efficiency. In this paper, it is shown that the spectrum of absorbance of silicon can be extended to longer wavelengths by proximity to a two-dimensional (2D) semiconductor. Photo-induced Hall effect, together with standard absorption spectroscopy, was employed to estimate the increase of photo-conversion efficiency of a 2D-platinum-diselenide/intrinsic-silicon heterostructure. The system shows a significantly higher absorption in the infrared as compared to the single films. Angle resolved X-ray Photoelectron Spectroscopy (XPS) confirm that a change of the band structure occurs in the silicon substrate at the interface between the two semiconductors. The results are interpreted in the framework of band-gap narrowing due to hole-confinement in the Si, induced by electron-confinement in the 2D film. This allows us to claim that the increase of photo-conversion efficiency in the Pt/PtSe2/Si sample is due to an enhancement of the light absorbance of silicon near the interface. Possible application of the effect in photo-voltaic cells is discussed.
AB - Because of its low-cost, silicon is the standard material for photovoltaic conversion. Yet, its band-edge absorption spectrum is narrower than the spectrum of the solar radiation, which reduces its conversion efficiency. In this paper, it is shown that the spectrum of absorbance of silicon can be extended to longer wavelengths by proximity to a two-dimensional (2D) semiconductor. Photo-induced Hall effect, together with standard absorption spectroscopy, was employed to estimate the increase of photo-conversion efficiency of a 2D-platinum-diselenide/intrinsic-silicon heterostructure. The system shows a significantly higher absorption in the infrared as compared to the single films. Angle resolved X-ray Photoelectron Spectroscopy (XPS) confirm that a change of the band structure occurs in the silicon substrate at the interface between the two semiconductors. The results are interpreted in the framework of band-gap narrowing due to hole-confinement in the Si, induced by electron-confinement in the 2D film. This allows us to claim that the increase of photo-conversion efficiency in the Pt/PtSe2/Si sample is due to an enhancement of the light absorbance of silicon near the interface. Possible application of the effect in photo-voltaic cells is discussed.
KW - 2D semiconductors
KW - Band-gap engineering
KW - Photo-conversion
KW - Transition-metal dichalcogenides
UR - http://www.scopus.com/inward/record.url?scp=85092476013&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2020.147803
DO - 10.1016/j.apsusc.2020.147803
M3 - Journal article
AN - SCOPUS:85092476013
SN - 0169-4332
VL - 538
JO - Applied Surface Science
JF - Applied Surface Science
M1 - 147803
ER -
