Spin-dependent current in silicon p-n junction diodes
We have used electrically detected spin-dependent paramagnetic resonance to investigate the non-equilibrium conductivity in a silicon diode. In order to create paramagnetic centers, we used diode with a polished surface (that includes p-n junction). The dependence of relative changes in the ampli...
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| Опубліковано в: : | Semiconductor Physics Quantum Electronics & Optoelectronics |
|---|---|
| Дата: | 2010 |
| Автори: | , , , |
| Формат: | Стаття |
| Мова: | English |
| Опубліковано: |
Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
2010
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| Цитувати: | Spin-dependent current in silicon p-n junction diodes/O.V. Tretyak, O.I. Kozonushchenko, K.V. Krivokhizha, A.S. Revenko // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2010. — Т. 13, № 1. — С. 95-97. — Бібліогр.: 10 назв. — англ. |
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Tretyak, O.V. Kozonushchenko, O.I. Krivokhizha, K.V. Revenko, A.S. 2017-05-26T18:01:45Z 2017-05-26T18:01:45Z 2010 Spin-dependent current in silicon p-n junction diodes/O.V. Tretyak, O.I. Kozonushchenko, K.V. Krivokhizha, A.S. Revenko // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2010. — Т. 13, № 1. — С. 95-97. — Бібліогр.: 10 назв. — англ. 1560-8034 PACS 73.20.-r, 73.40.-c, 85.30.Kk https://nasplib.isofts.kiev.ua/handle/123456789/117808 We have used electrically detected spin-dependent paramagnetic resonance to investigate the non-equilibrium conductivity in a silicon diode. In order to create paramagnetic centers, we used diode with a polished surface (that includes p-n junction). The dependence of relative changes in the amplitude of a signal under resonance conditions and the total value of current through the diode were investigated. We have found the presence of inversion channel on the surface of p-n junction and proposed the model of the influence of spin resonance on the channel conductivity. The upper value of the time constant inherent to the spin-dependent process was determined as approximately 10⁻⁶ s . The influence of the spin-dependent process on the charge state in inversion channel has been discussed. en Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України Semiconductor Physics Quantum Electronics & Optoelectronics Spin-dependent current in silicon p-n junction diodes Article published earlier |
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| title |
Spin-dependent current in silicon p-n junction diodes |
| spellingShingle |
Spin-dependent current in silicon p-n junction diodes Tretyak, O.V. Kozonushchenko, O.I. Krivokhizha, K.V. Revenko, A.S. |
| title_short |
Spin-dependent current in silicon p-n junction diodes |
| title_full |
Spin-dependent current in silicon p-n junction diodes |
| title_fullStr |
Spin-dependent current in silicon p-n junction diodes |
| title_full_unstemmed |
Spin-dependent current in silicon p-n junction diodes |
| title_sort |
spin-dependent current in silicon p-n junction diodes |
| author |
Tretyak, O.V. Kozonushchenko, O.I. Krivokhizha, K.V. Revenko, A.S. |
| author_facet |
Tretyak, O.V. Kozonushchenko, O.I. Krivokhizha, K.V. Revenko, A.S. |
| publishDate |
2010 |
| language |
English |
| container_title |
Semiconductor Physics Quantum Electronics & Optoelectronics |
| publisher |
Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
| format |
Article |
| description |
We have used electrically detected spin-dependent paramagnetic resonance to
investigate the non-equilibrium conductivity in a silicon diode. In order to create
paramagnetic centers, we used diode with a polished surface (that includes p-n junction).
The dependence of relative changes in the amplitude of a signal under resonance
conditions and the total value of current through the diode were investigated. We have
found the presence of inversion channel on the surface of p-n junction and proposed the
model of the influence of spin resonance on the channel conductivity. The upper value of
the time constant inherent to the spin-dependent process was determined as
approximately 10⁻⁶ s . The influence of the spin-dependent process on the charge state in
inversion channel has been discussed.
|
| issn |
1560-8034 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/117808 |
| citation_txt |
Spin-dependent current in silicon p-n junction diodes/O.V. Tretyak, O.I. Kozonushchenko, K.V. Krivokhizha, A.S. Revenko // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2010. — Т. 13, № 1. — С. 95-97. — Бібліогр.: 10 назв. — англ. |
| work_keys_str_mv |
AT tretyakov spindependentcurrentinsiliconpnjunctiondiodes AT kozonushchenkooi spindependentcurrentinsiliconpnjunctiondiodes AT krivokhizhakv spindependentcurrentinsiliconpnjunctiondiodes AT revenkoas spindependentcurrentinsiliconpnjunctiondiodes |
| first_indexed |
2025-11-25T23:07:36Z |
| last_indexed |
2025-11-25T23:07:36Z |
| _version_ |
1850578549161852928 |
| fulltext |
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2010. V. 13, N 1. P. 95-97.
© 2010, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
95
PACS 73.20.-r, 73.40.-c, 85.30.Kk
Spin-dependent current in silicon p-n junction diodes
O.V. Tretyak, O.I. Kozonushchenko, K.V. Krivokhizha, A.S. Revenko
Taras Shevchenko Kyiv National University, Radiophysics Department,
64, Volodymyrs’ka str., 01601 Kyiv, Ukraine
Abstract. We have used electrically detected spin-dependent paramagnetic resonance to
investigate the non-equilibrium conductivity in a silicon diode. In order to create
paramagnetic centers, we used diode with a polished surface (that includes p-n junction).
The dependence of relative changes in the amplitude of a signal under resonance
conditions and the total value of current through the diode were investigated. We have
found the presence of inversion channel on the surface of p-n junction and proposed the
model of the influence of spin resonance on the channel conductivity. The upper value of
the time constant inherent to the spin-dependent process was determined as
approximately s10 6 . The influence of the spin-dependent process on the charge state in
inversion channel has been discussed.
Keywords: EDMR, ESR, polished surface, paramagnetic states, inversion layer.
Manuscript received 13.10.09; accepted for publication 22.10.09; published online 30.12.09.
Non-equilibrium conductivity can depend on the spin
orientation of free carriers and charges in localized states
in the bandgap. Various experiments reported about
spin-dependent scattering [1], spin-dependent
recombination [2-4], spin-dependent hopping
conductivity [5]. Generally, the spin dependence of
current was observed via its changes under the
conditions of spin resonance. The theory of the spin-
dependent non-equilibrium conductivity under spin
resonance conditions was developed in [6].
The first report of a spin-dependent recombination
in mechanically treated silicon was presented in [2].
More appropriate object for spin-dependent
recombination in silicon is a diode with mechanically
treated surface, which includes p-n junction (Fig. 1).
A detailed juxtaposition of experimental data and
the theory of spin-dependent recombination (SDR) is
difficult, which is caused by the following reasons.
Up to now, in all works devoted to SDR
investigations the change of non-equilibrium
conductivity Δσs under spin resonance was always
compared with the total conductivity σ; in this paper we
operate with current since
I
I ss Δ
σ
Δσ
. The total
current IΣ consists of spin-dependent (Is) and spin-
independent (Ins) parts: IΣ = Is + Ins. As a rule, Is << Ins, so
an error can reach a value higher than one order.
Moreover, the dependence of
I
I sΔ
on temperature or
applied voltage may not represent the real process in
samples (in the case of using IΣ instead of Is as
denominator in
I
I sΔ
. Therefore, the information about
the total spin-dependent current (that should be used as
denominator) is a question of principle importance.
In this work, we present the attempt to estimate
(being based on experimental data) the value of Is and to
ascertain its mechanism in a silicon diode D-242 with
polished surface of p-n junction.
In silicon power diodes, the reverse current is
defined by generation-recombination mechanism
constanttime,
1
~I . After mechanical treatment
on the surface of diode, new channels of carrier
transportation are created, including the spin-dependent
one, IΣ = I0 + Is + Ins , where I0 is the current of unpolished
sample; Ins and Is are spin-independent current and spin-
dependent current, respectively (the latter appears after
mechanical treatment of the diode). Each of these currents
is inversely proportional to τ; so it is possible to assume
that determining the value of correspondent time constants
τ0 , τns , τs would lead to the possibility to define the ratio
ΔIs /I in a more accurate way.
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2010. V. 13, N 1. P. 95-97.
© 2010, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
96
Fig. 1. Diode with polished sides.
In Fig. 1 the schematic image of diode is shown.
Two sides are polished with diamond pasta with the
granular size of 3 to 5 μm. The experimental current-
voltage characteristics of the diode before and after
polishing are shown in Fig. 2. Before polishing, the
reverse current-voltage characteristic was in a good
correlation with the corresponding formulae for
generation-recombination mechanism of current (Fig. 2,
curve 4):
1kTeUe
τ
end
=Uj , (1)
where n is the equilibrium concentration of carriers, d –
width of space charge region, τ – time constant.
We have obtained the lifetime value for minority
carriers τ in the diode gained from the transient
characteristic [7]: it is about s10 5 . After polishing, the
reverse current increased significantly. Also, after
polishing the spin-dependent current in the diode was
observed under spin resonance conditions (and wasn’t
observed before polishing).
Fig. 2. Current-voltage characteristics (CVC) for the diodes:
1 – polished and 2 – untreated.
Fig. 3. Typical spectrum of EDMR.
The method of measuring the changes in
conductivity of minority carriers under spin resonance is
well known and presented, for example, in [2]. The
typical curve of ΔIs(H) is shown in Fig. 3. The maximum
of ΔIs /IΣ was about 610 .
In Fig. 4 the dependence of ΔIs on the modulation
frequency of the UHF at reverse voltage 15 V is shown.
In theory, the time constant of spin-dependent current τs
can be determined ([8]) from this dependence using the
formula
mod
0mod 4τ
1
thΔΔ
f
I=fI
s
, (2)
where ΔI0 is the amplitude at low frequencies. But in our
case, the value of τs cannot be determined because of
hardware limitations. It is clear from Fig. 4 that the time
constant of spin-dependent current τs is less than s10 6 .
All the aforementioned is the evidence of the
following assumption: both the increase of the reverse
current (due to polishing) and appearance of the spin-
dependent current are results not only of creation of
additional generation-recombination pairs, but also of
the creation of a new conductivity channel in subsurface
layers.
It is known from literature data [9, 10] that
mechanical treatment of the surface of silicon leads to
creation of an inversion layer. The increasing value of
reverse current, the absence of CVC saturation for the
polished diode (Fig. 2), the sign of changes in the
reverse current under spin resonance (increasing) and
minimum value of 610 s – all these aspects allow to
assert that the inversion layer of conductivity is created
in our case.
It is clear that for voltages higher than ≈15 V the
reverse current is determined mainly by conductivity of
the inversion channel that typically has ohmic
characteristics. For voltages lower than ≈15 V, the
generation-recombination mechanism is the main one in
transporting carriers through the p-n junction.
Assuming this model of the reverse current, it is
possible to assert that the increase of the reverse current
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2010. V. 13, N 1. P. 95-97.
© 2010, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
97
Fig. 4. Experimental data for the dependence of ΔIs on the
frequency of UHF modulation.
Fig. 5. Dependence of ΔIs /IΣ on the voltage.
under spin resonance conditions can be related with
increasing the space charge of paramagnetic centres at
the surface. The result of this – increase of the bending
of energetic bands and growth of conductivity – was
observed in our experiments. The dependence of ΔIs /IΣ
on U (Fig. 5) confirms this model. As an additional
evidence for the proposed model, considered can be the
fact of decreasing the effect’s value under illumination
of the diode polished side with strongly absorbed light.
The proposed mechanism of spin-dependent current
in the silicon diode with p-n junction with polished sides
(that includes p-n junction) is the main one in our case.
But this fact does not except involving the well known
spin-dependent generation-recombination mechanism.
The value of Is still remains unclear, but on the base of the
obtained experimental results we offer the new model of
spin-dependent current in diode, which matches
qualitatively with experimental data.
References
1. G. Toth, Collision dependent du spin entre electrons
de conduction et impurete’s paramagnetiques dans
les metaux et semiconductors: Effects sup les
proprietes de transport. – The Doctorat Etat Es-
Sciences Physiques, Paris, 1972, p.109.
2. D. Lepin, Spin-dependent recombination in silicon
// Phys. Rev. B 6(2), p. 436-444 (1972).
3. L.S. Mima, V.I. Strikha, O.V. Tretyak // Fizika
tekhnika poluprov. 14, p. 1328 (1980), in Russian.
4. L.S. Mima, O.V. Tretyak, Spin-dependent
recombination in semiconductors // Fizika tekhnika
poluprov. 15(9), p. 1729-1732 (1981), in Russian.
5. V.V. Ilchenko, O.V. Tretyak, Charge transport and
spin-dependent recombination in polycrystalline
silicon // Vestnik Kievskogo universiteta, ser. fizika,
1983, p. 24 (in Russian).
6. V.S. Lvov, L.S. Mima, O.V. Tretyak, Investigation
of spin-dependent recombination in semiconductors
// Preprint, vol. 182, Institute of Automation and
Electrometry, Siberian Branch of Russian Academy
of Sciences, Novosibirsk, Russia, 1982, p. 23 (in
Russian).
7. I.M. Vikulin, V.I. Stafeyev, Physics of
Semiconductor Devices. Radio i Svyaz Publ.,
Moscow, 1990, p. 40 (in Russian).
8. S.M. Ryvkin, Photoelectric Processes in
Semiconductors. Gos. izd-vo fiz. mat. lit., Moscow,
1963, p. 60 (in Russian).
9. V.V. Pasinkov, L.K. Chirkin, A.D. Shinkov,
Semiconductors Devices. Vysshaya Shkola Publ.,
Moscow, 1966, p. 122 (in Russian).
10. T.Ya. Gorbach, R.Yu. Holiney, I.M. Matiyuk et al.,
Electroreflectance spectroscopy and scanning
electron microscopy study of microrelief silicon
wafers with various surface pretreatments //
Semiconductor Physics, Quantum Electronics &
Optoelectronics 1(1), p. 66-70 (1998).
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2010. V. 13, N 1. P. 95-97.
PACS 73.20.-r, 73.40.-c, 85.30.Kk
Spin-dependent current in silicon p-n junction diodes
O.V. Tretyak, O.I. Kozonushchenko, K.V. Krivokhizha, A.S. Revenko
Taras Shevchenko Kyiv National University, Radiophysics Department,
64, Volodymyrs’ka str., 01601 Kyiv, Ukraine
Abstract. We have used electrically detected spin-dependent paramagnetic resonance to investigate the non-equilibrium conductivity in a silicon diode. In order to create paramagnetic centers, we used diode with a polished surface (that includes p-n junction). The dependence of relative changes in the amplitude of a signal under resonance conditions and the total value of current through the diode were investigated. We have found the presence of inversion channel on the surface of p-n junction and proposed the model of the influence of spin resonance on the channel conductivity. The upper value of the time constant inherent to the spin-dependent process was determined as approximately
s
10
6
-
. The influence of the spin-dependent process on the charge state in inversion channel has been discussed.
Keywords: EDMR, ESR, polished surface, paramagnetic states, inversion layer.
Manuscript received 13.10.09; accepted for publication 22.10.09; published online 30.12.09.
Non-equilibrium conductivity can depend on the spin orientation of free carriers and charges in localized states in the bandgap. Various experiments reported about spin-dependent scattering [1], spin-dependent recombination [2-4], spin-dependent hopping conductivity [5]. Generally, the spin dependence of current was observed via its changes under the conditions of spin resonance. The theory of the spin-dependent non-equilibrium conductivity under spin resonance conditions was developed in [6].
The first report of a spin-dependent recombination in mechanically treated silicon was presented in [2]. More appropriate object for spin-dependent recombination in silicon is a diode with mechanically treated surface, which includes p-n junction (Fig. 1).
A detailed juxtaposition of experimental data and the theory of spin-dependent recombination (SDR) is difficult, which is caused by the following reasons.
Up to now, in all works devoted to SDR investigations the change of non-equilibrium conductivity Δσs under spin resonance was always compared with the total conductivity σ; in this paper we operate with current since
÷
÷
ø
ö
ç
ç
è
æ
=
S
I
I
s
s
Δ
σ
Δσ
. The total current IΣ consists of spin-dependent (Is) and spin-independent (Ins) parts: IΣ = Is + Ins. As a rule, Is << Ins, so an error can reach a value higher than one order. Moreover, the dependence of
S
I
I
s
Δ
on temperature or applied voltage may not represent the real process in samples (in the case of using IΣ instead of Is as denominator in
÷
÷
ø
ö
I
I
s
Δ
. Therefore, the information about the total spin-dependent current (that should be used as denominator) is a question of principle importance.
In this work, we present the attempt to estimate (being based on experimental data) the value of Is and to ascertain its mechanism in a silicon diode D-242 with polished surface of p-n junction.
In silicon power diodes, the reverse current is defined by generation-recombination mechanism
÷
ø
ö
ç
è
æ
-
t
t
constant
time
,
1
~
I
. After mechanical treatment on the surface of diode, new channels of carrier transportation are created, including the spin-dependent one, IΣ = I0 + Is + Ins , where I0 is the current of unpolished sample; Ins and Is are spin-independent current and spin-dependent current, respectively (the latter appears after mechanical treatment of the diode). Each of these currents is inversely proportional to τ; so it is possible to assume that determining the value of correspondent time constants τ0 , τns , τs would lead to the possibility to define the ratio ΔIs /I in a more accurate way.
Fig. 1. Diode with polished sides.
In Fig. 1 the schematic image of diode is shown. Two sides are polished with diamond pasta with the granular size of 3 to 5 μm. The experimental current-voltage characteristics of the diode before and after polishing are shown in Fig. 2. Before polishing, the reverse current-voltage characteristic was in a good correlation with the corresponding formulae for generation-recombination mechanism of current (Fig. 2, curve 4):
(
)
(
)
1
-
kT
eU
e
τ
end
=
U
j
,
(1)
where n is the equilibrium concentration of carriers, d – width of space charge region, τ – time constant.
We have obtained the lifetime value for minority carriers τ in the diode gained from the transient characteristic [7]: it is about
s
10
5
-
. After polishing, the reverse current increased significantly. Also, after polishing the spin-dependent current in the diode was observed under spin resonance conditions (and wasn’t observed before polishing).
Fig. 2. Current-voltage characteristics (CVC) for the diodes: 1 – polished and 2 – untreated.
Fig. 3. Typical spectrum of EDMR.
The method of measuring the changes in conductivity of minority carriers under spin resonance is well known and presented, for example, in [2]. The typical curve of ΔIs(H) is shown in Fig. 3. The maximum of ΔIs /IΣ was about
6
10
-
.
In Fig. 4 the dependence of ΔIs on the modulation frequency of the UHF at reverse voltage 15 V is shown. In theory, the time constant of spin-dependent current τs can be determined ([8]) from this dependence using the formula
(
)
÷
÷
ø
ö
ç
ç
è
æ
mod
0
mod
4
τ
1
th
Δ
Δ
f
I
=
f
I
s
,
(2)
where ΔI0 is the amplitude at low frequencies. But in our case, the value of τs cannot be determined because of hardware limitations. It is clear from Fig. 4 that the time constant of spin-dependent current τs is less than
s
10
6
-
.
All the aforementioned is the evidence of the following assumption: both the increase of the reverse current (due to polishing) and appearance of the spin-dependent current are results not only of creation of additional generation-recombination pairs, but also of the creation of a new conductivity channel in subsurface layers.
It is known from literature data [9, 10] that mechanical treatment of the surface of silicon leads to creation of an inversion layer. The increasing value of reverse current, the absence of CVC saturation for the polished diode (Fig. 2), the sign of changes in the reverse current under spin resonance (increasing) and minimum value of
6
10
-
<
t
s
– all these aspects allow to assert that the inversion layer of conductivity is created in our case.
It is clear that for voltages higher than ≈15 V the reverse current is determined mainly by conductivity of the inversion channel that typically has ohmic characteristics. For voltages lower than ≈15 V, the generation-recombination mechanism is the main one in transporting carriers through the p-n junction.
Assuming this model of the reverse current, it is possible to assert that the increase of the reverse current under spin resonance conditions can be related with increasing the space charge of paramagnetic centres at the surface. The result of this – increase of the bending of energetic bands and growth of conductivity – was observed in our experiments. The dependence of ΔIs /IΣ on U (Fig. 5) confirms this model. As an additional evidence for the proposed model, considered can be the fact of decreasing the effect’s value under illumination of the diode polished side with strongly absorbed light.
The proposed mechanism of spin-dependent current in the silicon diode with p-n junction with polished sides (that includes p-n junction) is the main one in our case. But this fact does not except involving the well known spin-dependent generation-recombination mechanism. The value of Is still remains unclear, but on the base of the obtained experimental results we offer the new model of spin-dependent current in diode, which matches qualitatively with experimental data.
References
1. G. Toth, Collision dependent du spin entre electrons de conduction et impurete’s paramagnetiques dans les metaux et semiconductors: Effects sup les proprietes de transport. – The Doctorat Etat Es-Sciences Physiques, Paris, 1972, p.109.
2. D. Lepin, Spin-dependent recombination in silicon // Phys. Rev. B 6(2), p. 436-444 (1972).
3. L.S. Mima, V.I. Strikha, O.V. Tretyak // Fizika tekhnika poluprov. 14, p. 1328 (1980), in Russian.
4. L.S. Mima, O.V. Tretyak, Spin-dependent recombination in semiconductors // Fizika tekhnika poluprov. 15(9), p. 1729-1732 (1981), in Russian.
5. V.V. Ilchenko, O.V. Tretyak, Charge transport and spin-dependent recombination in polycrystalline silicon // Vestnik Kievskogo universiteta, ser. fizika, 1983, p. 24 (in Russian).
6. V.S. Lvov, L.S. Mima, O.V. Tretyak, Investigation of spin-dependent recombination in semiconductors // Preprint, vol. 182, Institute of Automation and Electrometry, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia, 1982, p. 23 (in Russian).
7. I.M. Vikulin, V.I. Stafeyev, Physics of Semiconductor Devices. Radio i Svyaz Publ., Moscow, 1990, p. 40 (in Russian).
8. S.M. Ryvkin, Photoelectric Processes in Semiconductors. Gos. izd-vo fiz. mat. lit., Moscow, 1963, p. 60 (in Russian).
9. V.V. Pasinkov, L.K. Chirkin, A.D. Shinkov, Semiconductors Devices. Vysshaya Shkola Publ., Moscow, 1966, p. 122 (in Russian).
10. T.Ya. Gorbach, R.Yu. Holiney, I.M. Matiyuk et al., Electroreflectance spectroscopy and scanning electron microscopy study of microrelief silicon wafers with various surface pretreatments // Semiconductor Physics, Quantum Electronics & Optoelectronics 1(1), p. 66-70 (1998).
�
Fig. 4. Experimental data for the dependence of ΔIs on the frequency of UHF modulation.
�
Fig. 5. Dependence of ΔIs /IΣ on the voltage.
© 2010, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
97
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