Journal Name:
Optik
Volume:
144
Issue:
2
Pages From:
340
To:
347
Date:
Tuesday, June 27, 2017
Abstract:
In the current study, we report the effect of insertion of a 200 nm thick Ge film between two
layers of InSe. The Ge sandwiched InSe films are studied by means of X-ray diffraction technique,
energy dispersion X-ray spectroscopy attached to a scanning electron microscope,
optical spectrophotometry and light power dependent photoconductivity. It was observed
that, The InSe prefers the growth of InSe monophase when deposited onto glass and the
growth of −In2Se3 when deposited onto InSe/Ge substrate. The three layers interface
(InSe/Ge/−In2Se3) exhibits a Ge induced crystallization process at annealing temperature
of 200 ◦C. The optical analysis has shown that the InSe films exhibit a redshift upon Ge
sandwiching. In addition, the conduction and valence bands offsets at the first interface
(InSe/Ge) and at the second (Ge/−In2Se3) interface are found to be 0.55 eV and 1.0 eV, and
0.40eVand 1.38 eV, respectively. Moreover, the photocurrent of the Ge sandwiched InSe
exhibited higher photocurrent values as compared to those of InSe. On the other hand,
the dielectric spectral analysis and modeling which lead to the identifying of the optical
conduction parameters presented by the plasmon frequency, electron scattering time, free
electron density and drift mobility have shown that the Ge sandwiching increased the drift
mobility values from 10 cm2/Vs to
∼42 cm2/Vs. The main plasmon frequency also increased
from 1.08 to 1.68 GHz.