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Semiconductor Physics, Quantum Electronics & Optoelectronics. 2005. V. 8, N 1. P. 046-052.
Investigation of the effect of external factors (heating, exposition to
radiation) on the electrophysical parameters of barrier
heterostructures p-AlGaAs–p-GaAs–n-GaAs
1Institute of Semiconductor Physics, NAS of Ukraine, 41, prospect Nauky, 03028 Kyiv, Ukraine
E-mail: dmitruk@isp.kiev.ua
Abstract. Over a wide temperature range (77…400 K), we studied I-V curves of
photoelectric converter (solar cell) prototypes made on the basis of p-AlxGa1-xAs–
p-GaAs–n-GaAs–n+
-GaAs heteroepitaxial structures grown on smooth or microrelief
n+
-GaAs substrates using the standard liquid phase epitaxy (LPE) and the capillary LPE
from a confined volume, as well as the effect of some external factors (thermal treatment
and 60Со γ-irradiation) on the current flow mechanisms. At temperatures ≤ 200 K, the
tunnel component of the forward current was predominant in all the smooth samples
studied up to the voltages close to 1 V, while at room temperatures all three components
(diffusion, recombination and tunnel) were of the same order. This is evidenced, in
particular, by the dependencys of the effective ideality factor on the applied voltage.
Predominance of the tunnel current component in a wide temperature range at small
biases was observed for all the solar cells obtained on the textured n+
-GaAs substrates. In
this case, an additional factor favoring the increase of the tunnel current component was
relief irregularities with small curvature radii.
Keywords: photoelectric converter, liquid phase epitaxy (LPE), microrelief, capillary
LPE, I-V curves, tunnel current component, solar cell, thermal treatment, γ-irradiation.
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