Results and discussion: On fig. 1 shows the dark CVC of the fabricated structure. An
analysis of the direct branch of the CVC showed that in the voltage range from 0 to 0.2 V, the
diffusion mode of current transfer is observed, and this segment is well approximated by an
exponential dependence of the form [3]:
ckT qV o e I I =
(1)
where q is the elementary charge; V is the electrical voltage applied to the structure; k is
the Boltzmann constant; T is the absolute temperature. Dependence (1) is typical for a "long"
p-n-diode, in which d/Ln > 1, here d is the base thickness, Lp is the diffusion length of
minority charge carriers in the base region of the structure [3].
The value of "c" in the exponent can be calculated directly from the experimental points
of the exponential section of the CVC curves using the relation:
)
/
ln(
1
2
1
2
I I V V kT q c −
=
(2)
The value of the indicator calculated from relation (2) was c=3.16
Behind the exponential section in the voltage range from 0.2 to 1 V there is an ohmic
dependence of the current - I =A-V, where A=1.03
∙
10-4 A/V. The appearance of an ohmic
region can be explained by modulation of the space charge by sticking centers in a high-
resistance base, the role of which is played by the epitaxial layer of the n-(Si
2
)
1-x
(GaN)
x
solid
solution. In the voltage range from 1.2 to 2.5 V, there is a power-law dependence of the
current - I =A-
Vα, with the power value α = 2
.7.
Fig.1. Direct branch of the current-voltage characteristic of the p-Si
–
n-(Si
2
)
1-x
(GaN)
x
structure in logarithmic scales.