Form 1

2017 Report Form for Collaboration with
Research Center for Biomedical Engineering

Year/month/date2024

Number13 /3/2018
date:

To Chairman, Board of Directors, Research Center for Biomedical Engineering

Affiliation
Title
Name
Address

ApplicantMoldova State University
Dr. Assoc. Profesor
Tamara Potlog
Chisinau, MD 2009 Moldova

Phone
Fax
E-mail373 69953854
373 22 244248
tpotlog@gmail.com
Report Form for Collaboration Research

Research Theme

Research Area

Research Period

Development of metal-phthalocyanine-perylene diimide derivates composite
materials for photodynamic terapy and photon harvesting in bulk
heterojunction photovoltaic devices
1. Biomaterials
2. Bioengineering
3. Functional molecules
4. Chemistry/Electrical Engineering/Mechanical Engineering/Materials Science

From:
1Date/month/Year
5 / 0 9 / 201

To: Date/month/Year
7 - 1 2 / 1 2/201

7

Applicant Organization
Name
Tamara Potlog

Department
Department of Physics and Engineering

Collaboration Partners
Research Center

intheTitle
Assoc. Prof.

Professor Hidenori Mimura RIE, Shizuoka University

Role
Experiments
and analysis

Research Results (Including Purpose, Results, Figures, etc.)

515(-101)

(211)
(013)

(301)
(202)

(002)
(200)

I, arb.un(312)oZnPc_thick_annealed 400 C
oZnPc_thin_annealed 400 C(101)(212)-β(013)-β(-213)-α(212)-β(212)-β(013)-β (013)-β(-213)-α*(200) - α* (00-2)-α*(-302)-α*(-302)-α (-302)-α(002)-α(002)-α****(200) - α(200) - α(00-2)-α (00-2)-α

*

3035

40

510*(212)-β(-311)-β*(211)-β(212)-β(-311)-β(211)-β20252θ, degree

8.0 µm
6.2 µm
4.0 µm2.1µm*(212)-β(-311)-βIntensity, arb.un.

*

10*(002)-α*(002)-α*(200)-β*(200)-β(002)-α(200)-β*(002)-α

Intensity, arb.un.

(002)-α(200)-βZnPc_thick (8 µm)_non- annealed _FA_(80)%)
ZnPc_thin _non-annealed_FA_(60)%
ZnPc_thick_non-annealed_FA_(98%)
ZnPc_thin_(2.1 µm)_non-annealed_FA_(98%)(002)-α1. Purpose of Research
The unsubstituted metal phthalocyanines have very low solubility in the majority of the solvents. Therefore, studies
focused on investigation of the solubility properties of ZnPc and of photosensitizer composite materials based on ZnPc
in different concentrations of solvent. Another objective was fabrication of thin films and annealing at different
temperatures, fabrication of the photovoltaic devices based on the developed thin films, characterization and elucidationof the optical, electrical properties in the thin films and devices.
2. Results
Commercially available zinc phthalocyanine (ZnPc) powder (98% purity) was purchased from Sigma Aldrich and wasused without further purification. The formic acid (FA) (99% purity) and dimethylformamide (DMF) (99.8% purity)
also, purchased from Sigma Aldrich were selected as the solvents for ZnPc. The ZnPc powder was added to the solventsof 60%, 80% and 98% concentrations of formic acid (FA). The X-ray diffractograms of the ZnPc films deposited fromFA solution with different concentrations, thicknesses and annealed at 400oC were studied.

1520252θ, degree30354010203040

50602θ, degree

Figure 1 The XRD patterns of ZnPc thin films synthesized on glass substrates from different concentration FA solutions, thickneses
and annealed at 400oC.

The XRD results reveal that all as-synthetized ZnPc thin films regardless of the thickness have both α- and β-phases
according to the JC-PDS cards No. 21-1986 and 39-1882, respectively. The XRD patterns of ZnPc films annealed at400 °C are assigned as β-ZnPc phase and are indexed as for monoclinic crystalline structure. FTIR spectra of thenon-annealed and annealed at 400oC, of ZnPc thin films were studied. The comparison of them shows that most of theFTIR bands change their position after annealing.

Figure 2 FTIR spectra of 98% FA solution ZnPc thin films of the non-annealed and annealed at 400oC. Absorption spectra of ZnPc
(right).

From the absorption spectra the increasing of the absorbance of ZnPc films with further increasing ofthe thickness are observed. Also, a shift towards the higher wavelength range for the thicker samples
is depicted. This shift of spectra indicates the decrease in the optical energy band gap (E g ).
The solution-processable Schottky diode solar cells glass/ITO/PEDOT:PSS/ZnPc(I 2 )/Al with different thicknesses ofZnPc layer were fabricated. The J-V characteristics of the device measured at AM1.5 condition (100 mW/cm2) were
measured and photovoltaic parameters were estimated (see table)

The
parameter

Vacuumevaporation
method [17]Chemical drop casting method,
8.0 µm and 6.2 µm, respectively

V OC (V)

0,89

1.03

0.97

J SC(μA∙cm-2)

2,8

8.2

5.6

FF

0.35

0.23

η, %

0.3

0.125

J, A/cm2

4,50x10-5

active ZnPc(I2)_6.2 µm
active ZnPc(I2)_ 8.0 µm

3,00x10-5
1,50x10-5

0,00-2,0 -1,5 -1,0 -0,5 0,0 0,5 1,0 1,5 2,0V,V-1,50x10-5-3,00x10-5Figure 3 The schematic configuration of solution processable glass/ITO/PEDOT: PSS/ZnPc( I 2 )/Al photovoltaic device (left) and theJ-V characteristics of solution processable glass/ITO/PEDOT: PSS/ZnPc (I 2 )/Al photovoltaic device (right).

ZnPc thin films of various thicknesses, ranging from 2.1 µm to 8.0 µm have been prepared from FA solutions ofdifferent concentration using the drop casting method. The XRD and FTIR analysis reveal the formation ofZn(HCOOH)Pc formate supramolecular complexes. Also, XRD analysis shows that the as deposited ZnPc films arepolycrystalline and contain a mixture of two crystalline phases: α- and β-. After annealing the improvement of the films
crystallinity shown by XRD analysis results in the increasing of the crystallites size from 20 nm to 32 nm and thepresence of the only β- phase. Further on, in this paper we demonstrate the fabrication of Schottky diode solar cells withhighest open circuit voltage on the base of optimized technology of ZnPc thin films. Moreover, ITO/PEDOT:PSS/ZnPc(I 2 )/Al photovoltaic devices have higher efficiency than the devices obtained with thermal vacuum
evaporation method. Recently, ZnPc has drawn considerable attention because of employing as hole-transporting
material in mixed-ion [FAP b I 3 ] 0.85 [MAP b B r3 ] 0.15 perovskite solar cells, that reaching the highest power conversion
efficiency (PCE), 17.5% so far for phthalocyanines. In order to improve the efficiency of solar cells with elaborated
ZnPc technology we need to develop the technology of an acceptor. Literature study show that we need to develop
technology of a new perovskite.

List of Publications Related to the Collaboration Research
1.T. Potlog, Vadim Furtuna, Cornel Rotaru, Roman Rusnac, Stefan Robu, Hidenori Mimura. Material Properties ofZinc Phthalocyanine from FA Solution and Application in Organic Solar Cells “Proceedings of 38th InternationalConference”, Tokyo, Japan, Nov. 2017, pp.39-45, ISBN 978-93-87405-42-4.
2. T. Potlog, E. Dauksta, A. Medvids, L. Ghimpu, C. Moise, K. Murakami, H. Mimura. “Effect of Laser Irradiationon the Refractive Index of the TiO 2 Thin Films. Optics and Laser Technology Journal, in press, under review, 2018

List of Presentations ( Conference, Meeting, etc)
1. “Structural Properties of Nanostructured Laser Annealed TiO 2 Thin Films” The 34th International Japan-Korea
Seminar on Ceramics, Hamamatsu, November, 2017 (oral presentation)
2. “Material Properties of Zinc Phthalocyanine from FA Solution and Application in Organic Solar Cells” 38th
Research World International Conference”, Tokyo, November, 2017

List of Awards

Research plan for the next year (from April 1, 2018 to March 31, 2019), if the collaboration research is continued.
Prior consent from the collaboration partner in the Research Center is necessary.
In the next year (2018) will be continued investigation of this materials for application in the photodynamic
therapy.
Photodynamic therapy investigations
Objectives of the research activities will be:
Firstly, evidence for the synthesis of metal-phthalocyanine-polymer photosensitizer composite material will be
provided by XRD, Raman spectroscopy, FTIR spectroscopy and by UV-VIS spectroscopy for identifying thedifferences determined by using various perylenediimide (PDI) derivatives concentrations and for identifying thespecific absorption bands, respectively. Secondly, the main research will refer to the assessment of two main
parameters featuring the phenomenon of photosensitization: the quantum yield of the singlet oxygen generation andthe singlet oxygen population lifetime. The singlet oxygen quantum yield is a quantitative measurement of theefficiency in which photosensitizes are able to use energy, in the form of light, to convert oxygen in the ground state to
the reactive species singlet oxygen. Singlet oxygen quantum yields of photosensitizes differ when measured in different
solvents. Therefore, lifetime of singlet oxygen as a function of solvent will be thirdly specific objective. Becauseof the different physical or chemical aspects of the production of the oxygen molecule in its singlet state, for singlet
oxygen detection, different methods, such as fluorescence imaging and fluorescence lifetime imaging microscopy(FLIM), fluorescence lifetime/transient absorption analysis systems (NIR photoluminescence lifetime spectrometer,
picoseconds fluorescence lifetime measurement...) and others designed by Hamamatsu Photonics for measuring
photoluminescence (PL) spectrum and PL lifetime in the NIR region will be used, if will be available in RIE, Shizuoka
University. The choice of light source will depend on the type of photosensitizers. Since PDT is typically constrained
to the “use of visible or near infrared light” consisting of localized delivery to tumors, as sources will be lasers,
incandescent light sources, light-emitting diodes coupled with optical fibers. Will be choose a longer wavelength oflight because increases the penetration depth into the tissue.