Физика полупроводниковых приборов
Photovoltaic and thermal effects at PbTe $p$–$n$ junction under CO$_2$ laser irradiation
S. Nemova,
B. Dzundzab,
L. Chernyakc,
Z. Dashevskyd a Peter the Great St. Petersburg Polytechnic University,
195251 St. Petersburg, Russia
b Vasyl Stefanyk Precarpathian National University,
76018 Ivano-Frankivsk, Ukraine
c Department of Physics, University of Central Florida,
Orlando, Fl 32816 USA
d Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva, 84105 Israel
Аннотация:
In this work, two effects appeared in PbTe
$p$–
$n$ junctions under long-wave irradiation by CO
$_2$ laser were investigated. The first effect was created by the optical absorption of long-wave photons in PbTe and caused by its photovoltaic effect. The mechanism of photoeffect is connected with the formation of electron–hole pairs by two-photon processes of absorption and separation of pairs at the
$p$–
$n$ junction. The second novel effect is related to the heating process and the formation of temperature difference at the
$p$–
$n$ junction. The main feature of PbTe semiconductor is a strong temperature dependence of static dielectric constant
$\varepsilon$. In this case, for PbTe
$p$–
$n$ junction it was created a barrier pyroelectric effect. PbTe
$p$–
$n$ junctions were fabricated employing indium donor diffusion into PbTe single crystals grown by the Chochrasky technique. Current–voltage and capacitance– voltage characteristics have been measured over a wide temperature range. The dark saturation current density was
$\sim$10
$^{-7}$ A/cm
$^2$ at
$T$ = 100 K. Two methods were used. The short-pulsed CO
$_2$ laser light (with a pulse duration of 150 ns) across the PbTe
$p$–
$n$ junction was used for the investigation of the photovoltaic effect. The continuous irradiation of CO
$_2$ was used for the investigation of the thermal effect and caused by its barrier pyroelectric effect (BPE). These two effects were investigated over the 40–150 K temperature range.
Ключевые слова:
PbTe semiconductor,
$p$–
$n$ junction, two-photon absorption, barrier pyroelectric effect.
Поступила в редакцию: 30.03.2021
Исправленный вариант: 30.03.2021
Принята в печать: 26.04.2021
Язык публикации: английский