Organic iso-type pentacene – lead phthalocyanine heterostructures
The photovoltaic properties of organic iso-type heterostructures based on pentacene (Pn) and lead phthalocyanine (PbPc) prepared by thermal deposition at different substrate temperatures (Ts) are investigated. It is shown that, at modulated illumination for Pn/PbPc heterostructures prepared at Тs...
Збережено в:
| Опубліковано в: : | Semiconductor Physics Quantum Electronics & Optoelectronics |
|---|---|
| Дата: | 2007 |
| Автори: | , |
| Формат: | Стаття |
| Мова: | English |
| Опубліковано: |
Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
2007
|
| Онлайн доступ: | https://nasplib.isofts.kiev.ua/handle/123456789/117920 |
| Теги: |
Додати тег
Немає тегів, Будьте першим, хто поставить тег для цього запису!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Organic iso-type pentacene – lead phthalocyanine heterostructures / Ya.I. Vertsimakha, P.M. Lutsyk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2007. — Т. 10, № 2. — С. 81-85. — Бібліогр.: 9 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
nasplib_isofts_kiev_ua-123456789-117920 |
|---|---|
| record_format |
dspace |
| spelling |
Vertsimakha, Ya.I. Lutsyk, P.M. 2017-05-27T12:23:56Z 2017-05-27T12:23:56Z 2007 Organic iso-type pentacene – lead phthalocyanine heterostructures / Ya.I. Vertsimakha, P.M. Lutsyk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2007. — Т. 10, № 2. — С. 81-85. — Бібліогр.: 9 назв. — англ. 1560-8034 PACS 78.66.-w, 79.60.Jv https://nasplib.isofts.kiev.ua/handle/123456789/117920 The photovoltaic properties of organic iso-type heterostructures based on pentacene (Pn) and lead phthalocyanine (PbPc) prepared by thermal deposition at different substrate temperatures (Ts) are investigated. It is shown that, at modulated illumination for Pn/PbPc heterostructures prepared at Тs = 300 K, the reversal of a sign is observed in photovoltage spectra. The properties of the structures are well described by the Van Opdorp model that indicates the presence of the high surface recombination rate of charge carriers at the interface of heterostructure components. At this, the contribution of heterostructure components to the photovoltage formation can be changed with unmodulated monochromatic additional illumination. In Pn/PbPc heterostructures prepared at Ts = 370 K, there is no reversal of the photovoltage sign, and the photovoltage is significantly (up to twice) higher in comparison with both heterostructures obtained at Ts = 300 K and separate layers of components (Pn and PbPc). This is the evidence for the low recombination rate of charge carriers at the interface of Pn/PbPc heterostructures prepared at Ts = 370 K en Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України Semiconductor Physics Quantum Electronics & Optoelectronics Organic iso-type pentacene – lead phthalocyanine heterostructures Article published earlier |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| title |
Organic iso-type pentacene – lead phthalocyanine heterostructures |
| spellingShingle |
Organic iso-type pentacene – lead phthalocyanine heterostructures Vertsimakha, Ya.I. Lutsyk, P.M. |
| title_short |
Organic iso-type pentacene – lead phthalocyanine heterostructures |
| title_full |
Organic iso-type pentacene – lead phthalocyanine heterostructures |
| title_fullStr |
Organic iso-type pentacene – lead phthalocyanine heterostructures |
| title_full_unstemmed |
Organic iso-type pentacene – lead phthalocyanine heterostructures |
| title_sort |
organic iso-type pentacene – lead phthalocyanine heterostructures |
| author |
Vertsimakha, Ya.I. Lutsyk, P.M. |
| author_facet |
Vertsimakha, Ya.I. Lutsyk, P.M. |
| publishDate |
2007 |
| language |
English |
| container_title |
Semiconductor Physics Quantum Electronics & Optoelectronics |
| publisher |
Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
| format |
Article |
| description |
The photovoltaic properties of organic iso-type heterostructures based on
pentacene (Pn) and lead phthalocyanine (PbPc) prepared by thermal deposition at
different substrate temperatures (Ts) are investigated. It is shown that, at modulated
illumination for Pn/PbPc heterostructures prepared at Тs = 300 K, the reversal of a sign is
observed in photovoltage spectra. The properties of the structures are well described by
the Van Opdorp model that indicates the presence of the high surface recombination rate
of charge carriers at the interface of heterostructure components. At this, the contribution
of heterostructure components to the photovoltage formation can be changed with
unmodulated monochromatic additional illumination. In Pn/PbPc heterostructures
prepared at Ts = 370 K, there is no reversal of the photovoltage sign, and the photovoltage
is significantly (up to twice) higher in comparison with both heterostructures
obtained at Ts = 300 K and separate layers of components (Pn and PbPc). This is the
evidence for the low recombination rate of charge carriers at the interface of Pn/PbPc
heterostructures prepared at Ts = 370 K
|
| issn |
1560-8034 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/117920 |
| citation_txt |
Organic iso-type pentacene – lead phthalocyanine heterostructures / Ya.I. Vertsimakha, P.M. Lutsyk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2007. — Т. 10, № 2. — С. 81-85. — Бібліогр.: 9 назв. — англ. |
| work_keys_str_mv |
AT vertsimakhayai organicisotypepentaceneleadphthalocyanineheterostructures AT lutsykpm organicisotypepentaceneleadphthalocyanineheterostructures |
| first_indexed |
2025-11-26T00:18:26Z |
| last_indexed |
2025-11-26T00:18:26Z |
| _version_ |
1850599760111599616 |
| fulltext |
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2007. V. 10, N 2. P. 81-85.
© 2007, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
81
PACS 78.66.-w, 79.60.Jv
Organic iso-type pentacene – lead phthalocyanine heterostructures
Ya.I. Vertsimakha, P.M. Lutsyk
Institute of Physics, NAS of Ukraine, 46, prospect Nauky, 03680 Kyiv, Ukraine
Phone: +380 44-525 09 12; fax +380 44-525 15 89
E-mails: yavertsi@iop.kiev.ua; lutsyk@univ.kiev.ua
Abstract. The photovoltaic properties of organic iso-type heterostructures based on
pentacene (Pn) and lead phthalocyanine (PbPc) prepared by thermal deposition at
different substrate temperatures (Ts) are investigated. It is shown that, at modulated
illumination for Pn/PbPc heterostructures prepared at Тs = 300 K, the reversal of a sign is
observed in photovoltage spectra. The properties of the structures are well described by
the Van Opdorp model that indicates the presence of the high surface recombination rate
of charge carriers at the interface of heterostructure components. At this, the contribution
of heterostructure components to the photovoltage formation can be changed with
unmodulated monochromatic additional illumination. In Pn/PbPc heterostructures
prepared at Ts = 370 K, there is no reversal of the photovoltage sign, and the photo-
voltage is significantly (up to twice) higher in comparison with both heterostructures
obtained at Ts = 300 K and separate layers of components (Pn and PbPc). This is the
evidence for the low recombination rate of charge carriers at the interface of Pn/PbPc
heterostructures prepared at Ts = 370 K.
Keywords: iso-type heterostructure, photovoltage spectra, lead phthalocyanine,
pentacene.
Manuscript received 14.02.07; accepted for publication 24.04.07; published online 19.10.07.
1. Introduction
The low efficiency of organic solar cells (SC) is caused
by a lot of reasons. One of these reasons is the high
series resistance that can be sufficiently decreased for
inorganic SC by the formation of p-p+ and n-n+ junctions
with the help of doping by appropriate dopants [1]. For
organic SC, this method of decreasing the series
resistance is inefficient and technologically complicated.
Therefore, to solve this problem, the use of p-p+ (n-n+)
heterostructures (HS) of the iso-type was suggested [2].
These HS can be readily prepared under the same
technical conditions simultaneously with obtaining the
aniso-type HS. The optimal selection of the components
can allow one to widen a spectral region of photo-
sensitivity and to increase the efficiency of the collection
of charge carriers, if the concentration of surface states
and the recombination rate of charge carriers are low at
the interface of HS.
To date, the photovoltaic properties of organic iso-
type HS is weakly investigated. Therefore, the aim of
this work is the study of the photovoltaic properties of
iso-type HS based on photosensitive organic semicon-
ductors and the ascertainment of the possibility to
prepare HS with low surface recombination rate at the
interface for the improvement of the performance of
organic SC.
2. Experimental
As a basic model object, we selected p-p+ HS based on
photosensitive organic semiconductor pentacene (Pn)
that was intensively used for the fabrication of organic
SC [3] and lead phthalocyanine (PbPc), whose
conductivity (in the monoclinic modification) is several
orders higher [4] than that of Pn [5, 6], and the spectral
region of photosensitivity of PbPc films is considerably
wider than that of Pn films [7]. The molecular structures
of these materials are presented in Fig. 1. As a
consequence of the component selection, the double-
layered Pn/PbPc structure (just as silicon) absorbs solar
light (Fig. 2, curves 1 and 2) in visible and near infrared
(IR) regions, which is required for the production of SC.
Thin-film iso-type HS were prepared by sequential
thermal deposition of Pn and PbPc layers on glass
substrates with a conductive and semitransparent indium
tin oxide (ITO) layer at different substrate temperatures
(Ts). At first, the Pn layer was deposited, and then the
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2007. V. 10, N 2. P. 81-85.
© 2007, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
82
Fig. 1. Molecular structure of Pn (top) and РbРс (bottom).
1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6
-0.3
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
0
1
3. ϕS (PbPc)
Add.back illum.
4. hν=2.18eV
5. hν=1.3eV
α, a.u.ϕ, mV
hν, eV
Ts=300K
hs Pn/PbPc
1. α, PbPc
2. α, Pn
Fig. 2. Absorption spectra of PbPc (1) and Pn (2) layers at
Ts=300 K and photovoltage spectra at illumination of PbPc
layer side for Pn/PbPc HS without (3) and with back additi-
onal illumination from LED with hν=2.18 (4) and 2.2 eV (5).
PbPc layer was deposited on it. The thicknesses of layers
were checked during the deposition by a change of the
frequency of a quartz resonator and, after the deposition,
by optical density spectra and atomic force microscopy
and amount to about (100±10) nm.
Absorption spectra (AS) were measured with a
double-beam “Hitachi-356” spectrophotometer. The
photovoltage measurements at modulated illumination
were carried out by the contactless method [8, 9].
Unmodulated monochromatic back additional
illumination was created by the illumination from
selected light-emitting diodes (LEDs) in the required
spectral range (IR LED with the quantum energy hν =
1.3 еV, whose illumination is absorbed by the PbPc
layer, and, respectively, green LED with hν = 2.18 еV
that is absorbed by the Pn layer). The additional
illumination power was measured by a calibrated
radiometer PPTN-02 based on a silicon photodiode.
3. Results and discussion
The photovoltage in the visible and near IR ranges of
iso-type HS under consideration was lower than the
photovoltage of aniso-type HS based on Pn and PbPc
layers (by 25 times for MPP/Pn HS and by 5 times for
MPP/PbPc HS [7], where MPP is methyl-substituted
perylene pigment).
The feature of Pn/PbPc HS obtained at Ts = 300 K
is the double reversal of a sign in the photovoltage
spectra at 2.1 and 2.6 eV (Fig. 2, curve 3). In this case,
the photovoltage spectra of these HS correlate with AS
of PbPc films in the range 1.2–1.8 eV (actually in the
transparency range of the Pn layer). In the range of
significant Pn layer absorption (1.8–2.5 eV), the
photovoltage reverse sign and the photovoltage spectra
are similar to the difference of photovoltage or the
absorbance of the components. According to the Van
Opdorp model for inorganic iso-type HS [1], such a
reversal of the sign in photovoltage spectra testifies to
the formation of high-concentration surface states
(centers of recombination and trapping of charge
carriers) near the interface of iso-type Pn/PbPc HS.
These states strongly change the equilibrium profile of
energy bands of the heterojunction. Charged states at the
interface of two layers result in the formation of two
depleted regions, and so the heterojunction can be
presented in the form of two Schottky photodiodes
engaged towards each other.
The model of two such Schottky photodiodes can
be used not only for the description of photoelectric
properties of iso-type heterostructures, but also for the
explanation of the influence of the back unmodulated
monochromatic additional illumination from appropriate
LEDs on parameters of the diode (the component of iso-
type HS). Thus, the photovoltage magnitude of the
negative component decreases with increase in the back
additional illumination intensity with the quantum
energy hν = 2.18 еV which predominantly excites the Pn
layer. The negative component disappears at the
intensity of back additional illumination by 20 times
higher than the basic modulated illumination (Fig. 2,
curve 4), and the photovoltage spectra of HS become
similar to AS of PbPc spectra. Vice versa, the HS
photovoltage magnitude of the negative component
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2007. V. 10, N 2. P. 81-85.
© 2007, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
83
increases by 20 % with rise in the intensity of the back
additional illumination of IR LEDs with hν = 1.3 еV
(Fig. 2, curve 5) that is absorbed by the PbPc layer. In
the case of IR additional illumination, the photovoltage
spectra of HS correlate with AS of Pn films, and the
magnitude of the positive component decreases by more
than 6 times.
In Pn/PbPc HS prepared at Ts = 370 K, there is no
sign reversal, and the maximal photovoltage is
practically two times higher than that for Pn/PbPc HS
prepared at Ts = 300 K and 10 times higher than the
surface photovoltage for ITO/PbPc structures (Fig. 3).
This shows that the concentration of recombination
centers of charge carriers is low at the interface of iso-
type Pn/PbPc HS prepared at Ts = 370 K. The photo-
voltage spectra of these HS are similar to the spectra of
the absorption coefficient and surface photovoltage of
PbPc films (Fig. 3, curves 1 and 5). But, in the region of
a band with maximum at 1.85 eV, the relative
photovoltage of Pn/PbPc HS is by 30 % higher than the
photovoltage of PbPc films. It is caused by the
contribution of non-equilibrium charge carriers photo-
generated in the Pn layer.
At the back additional illumination with hν =
1.3 еV that is absorbed by the PbPc layer, the
photovoltage in the region of a band with maximum at
1.85 еV becomes higher than the photovoltage of a band
with maximum at 1.4 еV. This is due to a decrease of the
PbPc contribution and illustrates the Pn contribution to
the formation of the photovoltage of Pn/PbPc HS (Fig. 3,
curve 2).
1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6
0.00
0.25
0.50
0.75
0.0
0.3
0.63. ϕS (PbPc)
Add.back illum.
4. hν=1.3eV
PbPc film
5. ϕS
α, a.u.ϕ, mV
hν, eV
Ts=370K
hs Pn/PbPc
1. α, PbPc
2. α, Pn
Fig. 3. Absorption spectra of PbPc (1) and Pn (2) layers at Ts =
370 K and photovoltage spectra at illumination of PbPc layer
side for Pn/PbPc HS without (3) and with back additional
illumination from LED with hν = 1.3 eV (4), and at
illumination of free surface side for PbPc layers (5).
According to the Van Opdorp model for iso-type
HS [1] at a high concentration of charge carriers
recombination centers, the open circuit voltage (or
photovoltage) can be expressed as
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
+⋅ϕ−⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
+⋅ϕ=ϕ
2
2
2
1
1
1 1ln1ln
S
R
S
R
I
I
I
I =
),1ln()1ln( 2211 PP ⋅γ+⋅ϕ−⋅γ+⋅ϕ=
where IR1 and IR2 are the photocurrent densities through
the corresponding Schottky photodiodes (i.e., diodes in
corresponding HS components), IS1 and IS2 are the
densities of the corresponding dark saturation currents.
In this case, the corresponding IR is proportional to the
intensity (power) of illumination (P) of the cor-
responding HS components. In our case, the PbPc
component has a positive photovoltage that corresponds
to the term with index 1, and the Pn component has
negative photovoltage and corresponds to the term with
index 2. If the illumination is absorbed in the PbPc layer
only (for example, IR light), then the dependence φ(Р)
will be fitted by one term of the equation only, while if
illumination is absorbed in both layers (green light), then
both terms of the equation will contribute, and φ(Р) can
reverse the sign. If the contribution of the second
(negative) term is neutralized by an additional
illumination that decreases the contribution of the
corresponding component (in our case, the Pn layer
contribution is decreased by the additional illumination
with hν = 2.18 еV, Fig. 2, curve 4), then the basic
contribution will be given by the first (positive) term.
0 1 2 3 4 5 6
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
Green (2.18eV) illumination
side: PbPc; Ts, K
1. 300
2. 370
+IR add. back illum. 1.3eV
3. 300
4. 370
ϕ, mV
P, a.u.
Fig. 4. Dependence of photovoltage for Pn/PbPc hetero-
structure on intensity of illumination with green (hν = 2.18 eV)
LED from PbPc layer side without (1, 2) and with (3, 4) back
additional illumination with hν = 1.3 еV; at Ts = 300 K (1, 3)
and 370 K (2, 4).
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2007. V. 10, N 2. P. 81-85.
© 2007, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
84
0.0 0.5 1.0 1.5 2.0 2.5
0.6
0.8
1.0
ϕ, mV
ϕS of hsPn/PbPc
back const ill.:
2.18eV; 1.3eV Ts, K
1. 3. 300
2. 4. 370
P, a.u.
Fig. 5. Dependence of photovoltage for Pn/PbPc hetero-
structure at illumination with hν = 1.45 еV from PbPc layer
side on intensity of unmodulated back additional illumination
with green (hν = 2.18 еV) (1, 2) and IR (hν = 1.3 еV) (3, 4)
LED; at Ts = 300 K (1, 3) and 370 K (2, 4).
To check the validity of this model in HS under
investigation, we measured the φ(Р) dependences in the
spectral range, where both components of HS without
and with the back unmodulated additional illumination
contribute to the photovoltage (Fig. 4). It is seen that the
IR additional illumination, which decreases a bend of
bands in the PbPc layer only, results in increasing the
photovoltage in HS prepared at Ts = 300 K (Fig. 4,
curves 1 and 3). In other words, the HS photovoltage
components compensate each other without additional
illumination, which is equivalent to the scheme of two
photodiodes engaged towards. In HS prepared at Тs =
370 K and with the same additional illumination, the
photovoltage decreases (Fig. 4, curves 2 and 4), i.e. the
photovoltage components unite without additional
illumination, which is equivalent to the scheme of two
photodiodes engaged in one direction [1].
The experimental dependences of φ(Р) are fitted by
the proposed equation and, in such a way, have testified
to the possibility of using the Van Opdorp model for
organic iso-type HS (Fig. 4). In this case, the photo-
voltage component of the high-energy-gap layer can
reverse the sign according to the expression for the short
circuit photocurrent in double-layer HS with high
recombination rate at the interface [1].
As is well known, the additional illumination
decreases the potential barrier (a bend of bands)
predominantly in the component that absorbs this
additional illumination [8]. The efficiency of a decrease
in the photovoltage will be higher in that component of
HS, where a change of the bend of a band is greater, i.e.
the potential barrier is higher. Therefore, the distribution
of space charge can be estimated at the interface of HS
components with the help of the influence of an
unmodulated monochromatic additional illumination on
the photovoltage. The additional illumination with hν =
1.3 еV is absorbed in the PbPc layer only, and one with
hν = 2.18 еV is absorbed predominantly in the Pn layer.
It is shown in Fig. 5 that the additional illumination with
hν = 1.3 еV more strongly affects the photovoltage of
Pn/PbPc HS than that with hν = 2.18 еV. However, it
should be noted that both additional illuminations affect
the photovoltage more strongly in HS prepared at 370 K.
According to the above results, the space charge is
basically localized in the PbPc layer for both types of
structures, and the bend of bands at the interface of HS is
greater for structures prepared at 370 K.
4. Conclusions
The obtained data allow us to consider that, at the
interface of organic iso-type Pn/PbPc heterostructures
prepared by thermal deposition on substrates at a
temperature of 300 K, the high concentration of the
recombination centers of charge carriers is formed. As a
consequence, the sign reversal is observed in
photovoltage spectra of these heterostructures. These
structures are described within a model of two
photodiodes engaged towards which proposed by Van
Opdorp for inorganic heterostructures. In this case, the
negative photovoltage component decreases at the
excitation of the Pn layer by the unmodulated additional
illumination with hν = 2.18 еV and, on the contrary,
increases at the excitation of the PbPc layer by the
unmodulated additional illumination with hν = 1.3 еV.
There is no sign reversal of photovoltage spectra
for Pn/PbPc HS prepared at 370 K, and the photovoltage
in the range of strong absorption is significantly higher
than the photovoltage of HS prepared at a substrate
temperature of 300 K. This indicates that the recom-
bination rate of charge carriers at the interface of
Pn/PbPc heterostructures decreases with increase in the
substrate temperature from 300 to 370 K. Therefore, the
iso-type Pn/PbPc heterostructures prepared at 370 K
allow one to widen the spectral range of the sunlight
absorption, to improve the coefficient of charge carrier
collection, and, as a result, can be used for increasing the
efficiency of organic solar cells.
References
1. B.L. Sharma, R.T. Purohit, Semiconductor Hetero-
junction. Pergamon Press, Oxford, UK, 1974.
2. Ya.I. Vertsimakha, Organic iso-type hetero-
structures and prospects of their practical
application for organic solar cells // Abstracts 4th
Intern. Confer. on “Electronic Processes in
Organic Materials” (ICEPOM-4) June 3-8, 2002,
Lviv, Ukraine, p. 45-46 (2002).
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2007. V. 10, N 2. P. 81-85.
© 2007, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
85
3. A.K. Pandey, J.-M. Nunzi, Efficient flexible and
thermally stable pentacene/C60 small molecule
based organic solar cells // Appl. Phys. Lett. 89,
p. 213506 (2006).
4. C. Hamann, H.-J. Höhne, F. Kersten, M. Müller,
F. Przyborowski, M. Starke, Switching effects on
polycrystalline films of lead phthalocyanine (PbPc)
// Phys. status solidi (a) 50, p. K189-K192 (1978);
K. Ukei, K. Takamoto, E. Kanda // Phys. Lett. A
45, p. 345 (1973).
5. Ch.-K. Song, M.-K. Jung, B.-W. Koo, Pentacene
thin film transistor improved by thermal annealing
// J. Korean Phys. Soc. 39, p. S271-S274 (2001).
6. J. Puigdollers, C. Voz, A. Orpella, I. Martin,
M. Vetter, R. Alcubilla, Pentacene thin-films
obtained by thermal evaporation in high vacuum //
Thin Solid Films 427, p. 367-370 (2003).
7. Ya. Vertsimakha, P. Lutsyk, p-n type
heterostructures based on N, N`-dimethyl perylene-
tetracarboxylic acid diimide // Molec. Cryst. Liquid
Cryst. 467, p. 107-122 (2007).
8. I.A. Akimov, The investigation of internal
photoelectric effect in semiconductors by
condenser method // Optiko-Mekhanicheskaya
Promyshlennost’ 5, p. 4-13 (1966) (in Russian).
9. P. Lutsyk, J. Misiewic, A. Podhorodecki, Ya. Ver-
tsimakha, Photovoltaic properties of SnCl2Pc films
and SnCl2Pc/pentacene heterostructures // Solar
Energy Mater. Solar Cells 91, p. 47-53 (2007).
|