rus
Issue #2/2020
K. F. Latypov, M. Yu. Dolomatov
ESTIMATION OF THE BANDGAP WIDTH OF ORGANIC SEMICONDUCTORS PHOTOCONDUCTIVITY BY INTEGRAL PARAMETERS OF AUTOCORRELATIONAL FUNCTIONS
ESTIMATION OF THE BANDGAP WIDTH OF ORGANIC SEMICONDUCTORS PHOTOCONDUCTIVITY BY INTEGRAL PARAMETERS OF AUTOCORRELATIONAL FUNCTIONS
DOI: 10.22184/1993-7296.FRos.2020.14.2.184.191
As a result of experiments with spectra of organic semiconductors molecules, a new physical effect was found. It connects the bandgap width of photoconductivity and the integral autocorrelational characteristics of absorption spectra in the visible and UV‑range. An integral parameter of autocorrelational function (IACF) was taken as a phenomenological characteristics.
The parameter reflects a correlation of electronic states under molecules excitations. The regularity found can be explained by the dependence of bandgap width on electronic states that govern electron transfusions from the valence to the conduction band. Since the autocorrelational function of spectra reflects interconnection between resonant electronic states which create optical spectra; then, the IACF, on the one hand, reflects correlational interactions of electron, on the other hand, electron states energy. That is why we can speak about correlation between the mentioned parameter with the bandgap width that is connected to relevant activation energy of photoconductivity. The discovered regularities are confirmed by
investigations in organic semiconductors rows on the base of anthraquinones and oxypyrenes. The regularities allow to evaluate the bandgap width of photoconductivity of organic semiconductors on the base of anthraquinones and oxypyrenes by the IPAF of optical absorption spectra in the visible and UV ranges with the consistent accuracy for practical applications ±(0,01–0,02) eV. The results of research can be applied in molecular
electronics, photonics, nano and microelectronics, in construction of quantum generators on organic semiconductors base as well.
As a result of experiments with spectra of organic semiconductors molecules, a new physical effect was found. It connects the bandgap width of photoconductivity and the integral autocorrelational characteristics of absorption spectra in the visible and UV‑range. An integral parameter of autocorrelational function (IACF) was taken as a phenomenological characteristics.
The parameter reflects a correlation of electronic states under molecules excitations. The regularity found can be explained by the dependence of bandgap width on electronic states that govern electron transfusions from the valence to the conduction band. Since the autocorrelational function of spectra reflects interconnection between resonant electronic states which create optical spectra; then, the IACF, on the one hand, reflects correlational interactions of electron, on the other hand, electron states energy. That is why we can speak about correlation between the mentioned parameter with the bandgap width that is connected to relevant activation energy of photoconductivity. The discovered regularities are confirmed by
investigations in organic semiconductors rows on the base of anthraquinones and oxypyrenes. The regularities allow to evaluate the bandgap width of photoconductivity of organic semiconductors on the base of anthraquinones and oxypyrenes by the IPAF of optical absorption spectra in the visible and UV ranges with the consistent accuracy for practical applications ±(0,01–0,02) eV. The results of research can be applied in molecular
electronics, photonics, nano and microelectronics, in construction of quantum generators on organic semiconductors base as well.
ESTIMATION OF THE BANDGAP WIDTH OF ORGANIC SEMICONDUCTORS PHOTOCONDUCTIVITY BY INTEGRAL PARAMETERS OF AUTOCORRELATIONAL FUNCTIONS
K. F. Latypov1, M. Yu. Dolomatov 1, 2
Federal State Budgetary Educational Institution of Higher Education «Bashkir State University» (BashSU), www.bashedu.ru; Ufa, Russia
Federal State Budgetary Educational Institution of Higher Education «Ufa State Petroleum Technical University» (UGNTU), http://rusoil.net, Ufa, Russia
As a result of experiments with spectra of organic semiconductors molecules, a new physical effect was found that connects the bandgap width of photoconductivity and the integral autocorrelational characteristics of absorption spectra in the visible and UV range. An integral parameter of autocorrelational function (IACF) was taken as a phenomenological characteristics. The parameter reflects a correlation of electronic states under molecules excitations. The regularity found can be explained by the dependence of bandgap width on electronic states that govern electron transfusions from the valence to the conduction band. Since the autocorrelational function of spectra reflects interconnection between resonant electronic states which create optical spectra; then, the IACF, on the one hand, reflects correlational interactions of electron, on the other hand, electron states energy. That is why we can speak about correlation between the mentioned parameter with the bandgap width that is connected to relevant activation energy of photoconductivity.
The discovered regularities are confirmed by investigations in organic semiconductors rows on the base of anthraquinones and oxypyrenes. The regularities allow to evaluate the bandgap width of photoconductivity of organic semiconductors on the base of anthraquinones and oxypyrenes by the IPAF of optical absorption spectra in the visible and UV ranges with the consistent accuracy for practical applications ±(0,01–0,02) eV. The results of research can be applied in molecular electronics, photonics, nano and microelectronics, in construction of quantum generators on organic semiconductors base as well.
Keywords: bandgap width of photoconductivity, integral parameter of autocorrelational function, electronic spectra, optical absorption spectroscopy
Received: 15.12.2019
Accepted: 14.01.2020
INTRODUCTION
Knowledge of the bandgap width of photoconductivity is essential for optimizing the operation of LEDs, photoelectronic converters and sensors based on organic semiconductors.
Evaluation of the bandgap width of photoconductivity () can be carried out by calculation and experimentally. Currently, quantum-mechanical methods for estimating the density functional method in the TD-DFT BLYP approximation are known for calculating () [1]. This method assumes the use of a non-stationary equation for the density functional, which makes it possible to estimate the time of electronic transitions from the ground to the excited state ∆E ∆τ ≥ h, and therefore the bandgap width of photoconductivity. These methods suggest that the bandgap width of photoconductivity is equal to the excitation energy of electronic states in the UV range [1].
The disadvantages of the calculation approach include the impossibility of applying to multicomponent semiconductor systems and complex organic semiconductors.
There are methods for the experimental determination of ∆E ∆τ ≥ h by the fundamental band of the absorption spectrum k2 = f(λ) [2] where k is the absorption coefficient, 102 m2 / kg; f(λ) is the distribution density of the square of the absorption coefficient, 104 m4 / kg2; λ is the wavelength of electromagnetic radiation of a monochromatic source, nm. is determined by extrapolating the fundamental absorption band of the spectrum and determining the corresponding wavelength λ0 by the formula:
, (1)
where h is the Planck constant, 6.13567 • 10–15 eV•s; c is the speed of light in vacuum, 299793 m / s; λ0 is the boundary wavelength of electromagnetic radiation, determined by extrapolation, nm
Despite its apparent simplicity, the method has several disadvantages:
the inability to use for multicomponent semiconductors consisting of two or more compounds;
the inability of using complex organic semiconductors, in which it is difficult to separate the absorption spectra without resorting to the Fourier transform;
inapplicability for organic semiconductors for which there is no comprehensive information on the composition and structure of molecules.
We found an effect that eliminates these shortcomings. Numerous studies have shown the existence of a relationship between and the integral parameter of the autocorrelational function.
The aim of the research was to study the integral correlation phenomenological characteristics of the optical spectra of organic molecules based on anthraquinones and hydroxypyrenes, which are known to have semiconductor properties [3–5]. In particular, the study of the relationships between the integral parameters of autocorrelational functions (ACF) of the optical spectrum and the bandgap width of photoconductivity in the framework of the hypothesis of strong correlation of electronic states. The optical spectra of organic semiconductors (anthraquinones and methoxypyrenes) are characterized by a combination of overlapping bands with maxima at λ = 240, 250, and 280 nm.
In earlier researches [6, 7], the authors’ approach to the study of characteristics was that they calculated the phenomenological parameter of the spectrum without separating individual bands using the Fourier transform method. It was shown in [7] that the autocorrelational function (ACF) is a measure of the interaction of electronic states. As follows from a theoretical and experimental study of signals [8–10], ACF has the form:
, (2)
where S(ω), S(ω + ∆ω) are the spectral distribution functions of the intensities of the absorbed radiation at frequencies ω and ω + ∆ω, respectively. Using the Wiener-Khinchin theorem [11], the autocorrelational function can be expressed in terms of resonant frequencies:
. (3)
Formula (3) directly reflects the relationship of the energy spectrum of resonant electronic states and ACF. However, the search for these frequencies using the Fourier transform is not the task of the study.
In this paper, we consider the near UV and visible range of the spectrum in the range 190–760 nm (6.53–10.63 eV), and instead of the ACF, we use the integral parameter of this function (IACF), which represents a certain integral with a specific numerical value in the energy scale:
, (4)
where E is the radiation energy, eV; E1, E2 – spectrum range, eV; S(E) and S(E + ΔE) are the spectral distribution functions of the radiation absorption intensities in the visible and UV spectra for the energies E and E + ΔE, respectively.
The IACF is an integral transformation in the form of the product of the main and delayed logarithmic functions of the molar absorption coefficient ε(E), i. e. S(E) = lg ε(E). Then
, (5)
IA has an eV dimension.
In previous studies [7, 12], it was found that IACF is associated with ionization potentials and electron affinity of organic molecules. This makes it possible to assume the existence of a relationship between the IACF and .
To test this hypothesis, we studied the interrelationships of the IACF, determined from the experimental absorption spectra of heterocyclic molecules with , obtained by determining the fundamental absorption band along the edge [2]. In the calculations, ergodicity and stationarity of the signal are allowed, i. e. the time of light passage through the sample under study is much shorter than the relaxation time of electronic states.
EXPERIMENT RESULTS
The objects of study in this work were the spectra of heteroatomic organic semiconductors of a number of anthraquinone and oxypyrene, the spectra of individual compounds are shown in Fig. 1. As is known, the spectra of heteroatomic organic semiconductors are characterized by absorption bands caused by π → π* transitions due to the presence of a conjugated chain, they are characterized by high intensity and weakly intense n → π*, n → σ* symmetry transitions.
Absorption spectra were recorded in the range from 190 to 760 nm with a step of 1 nm using an SF 2000 automatic electronic spectrometer, and the results were displayed on a computer via ADC. The spectra of individual compounds were taken from the database [13–14].
Subsequently, the calculation was performed on the energy scale of the spectrum.
By processing the data of spectroscopy and calculations by extrapolating the fundamental absorption band using the least square method, the statistical relationships of and IACF were studied. The established dependences for the semiconductors of a number of anthraquinones (Fig. 2 a) and oxypyrenes (Fig. 2 b) have the form:
, (6)
where the constant D1 characterizes the bandgap width of photoconductivity in the absence of autocorrelation of electronic states (IA = 0), the constant D2 reflects a decrease in the bandgap width of photoconductivity with increasing correlation energy of electron repulsion. The values of D1 and D2 for a number of anthraquinones and hydroxypyrenes, as well as calculations of statistical errors, are given in Table. 1.
According to the results of the experiment, for anthraquinones is in the range 1.31–1.43 eV, and for oxypyrenes, respectively, 1.40–1.48 eV. The obtained dependence is statistically substantiated: thus, the determination coefficient R2 is in the range from 0.72 to 0.89, the average relative error is in the range from 0.44 to 1.16%.
As an example, the values of organic semiconductors were determined: 1-dimethylamino 2,3,4-trifluororantraquinone and 11-hydroxybenzo[b]pyrene. The determination was made at the edge of the fundamental band of the absorption spectrum and according to dependence (6) (Table 2). It follows from Table 2 that the average relative error in determining the bandgap width of photoconductivity of organic semiconductors from dependence (6) in comparison with the optical method along the edge of the fundamental band is 6.57%. Therefore, the proposed method for determining the bandgap width of photoconductivity gives adequate results in comparison with the known analogue.
Thus, it is possible to determine the bandgap width of photoconductivity directly from the spectrum by the IACF.
CONCLUSIONS
During the experimental study of optical spectra in the visible and UV ranges for organic heteroatomic semiconductors of the anthraquinone and oxypyrene series, an effect was established that relates the bandgap width of photoconductivity to the integral parameter of the autocorrelational function of the absorption spectrum, which characterizes the interaction of excited electronic states.
The established regularities make it possible to estimate the bandgap width of photoconductivity of organic semiconductors of anthraquinone and oxypyrene series by the integral parameter of autocorrelational function of optical absorption spectra in the UV and visible regions with an accuracy of ±(0.01–0.02) eV sufficient for practical applications. Thus, providing the correct information on the width of the conduction band in organic semiconductors without quantum calculations and separation of spectral bands using the Fourier transform.
The results obtained are intended for use in semiconductor research for the creation of photoelectronic converters, as well as in the development of quantum generators.
The idea of the experiment belongs to M. Dolomatov, schematic design and processing of the results was made by K. Latypov.
REFERENCE
YUrenev P. V., SHCHerbinin A. V., Stepanov N. F. Primenimost’ metodov TD–DFT dlya rascheta elektronnogo spektra pogloshcheniya geksaaminoruteniya (p) v vodnom rastvore. ZHurnal fizicheskoj himii. 2010; 84(1): 44–48.
Bodnar I. V. On the band gap of Cu2ZnSn(S[x]Se[1-x]). Semiconductors. 2015;49: 1145–1148.doi:10.1134 / S1063782615090079.
Simon J., Andre J.-J. Molecular Semiconductors: Photoelectrical Properties and Solar Cells / 1-st ed. – Berlin, Heidelberg, New York, Tokio: Springer-Verlag. 1985.
Vodzinskij V. YU. Organicheskie poluprovodniki / Uchebnoe posobie. – N. Novgorod: NGTU im. R. E. Alekseeva. 2015.
Fajn V. YA. 9, 10-antrahinony i ih primenenie. – M.: Centr fotohimii RAN. 1999.
Tihonov V. I. Statisticheskaya radiofizika. – M.: Radio i svyaz’, 1982.
Rytov S. M. Vvedenie v statisticheskuyu radiofiziku / ch. 1. Sluchajnye processy. – M.: Nauka. 1976.
SHmidt V. Opticheskaya spektroskopiya dlya himikov i biologov. – M.: Tekhnosfera. 2007; 189–194.
Leon W., Couch I. Digital and Analog Communications Systems. 6 ed. – New Jersey: Prentice Hall. 2001; 406–409.
Dolomatov M. YU., Kovaleva E. A. Avtokorrelyacionnyj analiz spektrov pogloshcheniya elektromagnitnogo izlucheniya molekulami policiklicheskih soedinenij v petagercevoj oblasti. Elektromagnitnye volny i elektronnye sistemy. 2016; 21(9): 20–24.
Dolomatov M. YU., Latypov K. F. Opredelenie potenciala ionizacii geterociklicheskih molekul po opticheskim spektram pogloshcheniya elektromagnitnogo izlucheniya v vidimoj i UF oblasti. Fotonika. 2017; 4: 78–82.
Dolomatov M. YU., Latypov K. F. Primenenie metodov statisticheskoj radiofiziki dlya ocenki potencialov ionizacii i srodstva k elektronu molekul po spektram pogloshcheniya elektromagnitnogo izlucheniya v petagercevoj oblasti. Elektromagnitnye volny i elektronnye sistemy. 2017; 22(2):54–60.
Koptyug V. A. Atlas spektrov aromaticheskih i geterociklicheskih soedinenij. Vypusk 13. Spektry pogloshcheniya proizvodnyh antrahinona 9,10 v infrakrasnoj, ul’trafioletovoj i vidimoj oblastyah. Novosibirsk: IOH; NIC MS, 1977.
Bol’shakov G. F., Vatago V. S., Agrest F. B. Ul’tra-fioletovye spektry geteroorganicheskih soedinenij. – L: Himiya, 1969.
ABOUT AUTHORS
Latypov Kamil Faridovich, graduate student, kamil-latipov@rambler.ru, Bashkir State University, www.bashedu.ru, Ufa, Russia
ORCID: 0000-0003-1581-662X
Dolmatov Michel Yurievich, Dr. of Chemical Sciences, dolmatov@gmail.com, Башкирский Bashkir State University, www.bashedu.ru, Ufa State Petroleum Technological University, http://rusoil.net, Ufa, Russia
ORCID: 0000-0003-2677-6993
K. F. Latypov1, M. Yu. Dolomatov 1, 2
Federal State Budgetary Educational Institution of Higher Education «Bashkir State University» (BashSU), www.bashedu.ru; Ufa, Russia
Federal State Budgetary Educational Institution of Higher Education «Ufa State Petroleum Technical University» (UGNTU), http://rusoil.net, Ufa, Russia
As a result of experiments with spectra of organic semiconductors molecules, a new physical effect was found that connects the bandgap width of photoconductivity and the integral autocorrelational characteristics of absorption spectra in the visible and UV range. An integral parameter of autocorrelational function (IACF) was taken as a phenomenological characteristics. The parameter reflects a correlation of electronic states under molecules excitations. The regularity found can be explained by the dependence of bandgap width on electronic states that govern electron transfusions from the valence to the conduction band. Since the autocorrelational function of spectra reflects interconnection between resonant electronic states which create optical spectra; then, the IACF, on the one hand, reflects correlational interactions of electron, on the other hand, electron states energy. That is why we can speak about correlation between the mentioned parameter with the bandgap width that is connected to relevant activation energy of photoconductivity.
The discovered regularities are confirmed by investigations in organic semiconductors rows on the base of anthraquinones and oxypyrenes. The regularities allow to evaluate the bandgap width of photoconductivity of organic semiconductors on the base of anthraquinones and oxypyrenes by the IPAF of optical absorption spectra in the visible and UV ranges with the consistent accuracy for practical applications ±(0,01–0,02) eV. The results of research can be applied in molecular electronics, photonics, nano and microelectronics, in construction of quantum generators on organic semiconductors base as well.
Keywords: bandgap width of photoconductivity, integral parameter of autocorrelational function, electronic spectra, optical absorption spectroscopy
Received: 15.12.2019
Accepted: 14.01.2020
INTRODUCTION
Knowledge of the bandgap width of photoconductivity is essential for optimizing the operation of LEDs, photoelectronic converters and sensors based on organic semiconductors.
Evaluation of the bandgap width of photoconductivity () can be carried out by calculation and experimentally. Currently, quantum-mechanical methods for estimating the density functional method in the TD-DFT BLYP approximation are known for calculating () [1]. This method assumes the use of a non-stationary equation for the density functional, which makes it possible to estimate the time of electronic transitions from the ground to the excited state ∆E ∆τ ≥ h, and therefore the bandgap width of photoconductivity. These methods suggest that the bandgap width of photoconductivity is equal to the excitation energy of electronic states in the UV range [1].
The disadvantages of the calculation approach include the impossibility of applying to multicomponent semiconductor systems and complex organic semiconductors.
There are methods for the experimental determination of ∆E ∆τ ≥ h by the fundamental band of the absorption spectrum k2 = f(λ) [2] where k is the absorption coefficient, 102 m2 / kg; f(λ) is the distribution density of the square of the absorption coefficient, 104 m4 / kg2; λ is the wavelength of electromagnetic radiation of a monochromatic source, nm. is determined by extrapolating the fundamental absorption band of the spectrum and determining the corresponding wavelength λ0 by the formula:
, (1)
where h is the Planck constant, 6.13567 • 10–15 eV•s; c is the speed of light in vacuum, 299793 m / s; λ0 is the boundary wavelength of electromagnetic radiation, determined by extrapolation, nm
Despite its apparent simplicity, the method has several disadvantages:
the inability to use for multicomponent semiconductors consisting of two or more compounds;
the inability of using complex organic semiconductors, in which it is difficult to separate the absorption spectra without resorting to the Fourier transform;
inapplicability for organic semiconductors for which there is no comprehensive information on the composition and structure of molecules.
We found an effect that eliminates these shortcomings. Numerous studies have shown the existence of a relationship between and the integral parameter of the autocorrelational function.
The aim of the research was to study the integral correlation phenomenological characteristics of the optical spectra of organic molecules based on anthraquinones and hydroxypyrenes, which are known to have semiconductor properties [3–5]. In particular, the study of the relationships between the integral parameters of autocorrelational functions (ACF) of the optical spectrum and the bandgap width of photoconductivity in the framework of the hypothesis of strong correlation of electronic states. The optical spectra of organic semiconductors (anthraquinones and methoxypyrenes) are characterized by a combination of overlapping bands with maxima at λ = 240, 250, and 280 nm.
In earlier researches [6, 7], the authors’ approach to the study of characteristics was that they calculated the phenomenological parameter of the spectrum without separating individual bands using the Fourier transform method. It was shown in [7] that the autocorrelational function (ACF) is a measure of the interaction of electronic states. As follows from a theoretical and experimental study of signals [8–10], ACF has the form:
, (2)
where S(ω), S(ω + ∆ω) are the spectral distribution functions of the intensities of the absorbed radiation at frequencies ω and ω + ∆ω, respectively. Using the Wiener-Khinchin theorem [11], the autocorrelational function can be expressed in terms of resonant frequencies:
. (3)
Formula (3) directly reflects the relationship of the energy spectrum of resonant electronic states and ACF. However, the search for these frequencies using the Fourier transform is not the task of the study.
In this paper, we consider the near UV and visible range of the spectrum in the range 190–760 nm (6.53–10.63 eV), and instead of the ACF, we use the integral parameter of this function (IACF), which represents a certain integral with a specific numerical value in the energy scale:
, (4)
where E is the radiation energy, eV; E1, E2 – spectrum range, eV; S(E) and S(E + ΔE) are the spectral distribution functions of the radiation absorption intensities in the visible and UV spectra for the energies E and E + ΔE, respectively.
The IACF is an integral transformation in the form of the product of the main and delayed logarithmic functions of the molar absorption coefficient ε(E), i. e. S(E) = lg ε(E). Then
, (5)
IA has an eV dimension.
In previous studies [7, 12], it was found that IACF is associated with ionization potentials and electron affinity of organic molecules. This makes it possible to assume the existence of a relationship between the IACF and .
To test this hypothesis, we studied the interrelationships of the IACF, determined from the experimental absorption spectra of heterocyclic molecules with , obtained by determining the fundamental absorption band along the edge [2]. In the calculations, ergodicity and stationarity of the signal are allowed, i. e. the time of light passage through the sample under study is much shorter than the relaxation time of electronic states.
EXPERIMENT RESULTS
The objects of study in this work were the spectra of heteroatomic organic semiconductors of a number of anthraquinone and oxypyrene, the spectra of individual compounds are shown in Fig. 1. As is known, the spectra of heteroatomic organic semiconductors are characterized by absorption bands caused by π → π* transitions due to the presence of a conjugated chain, they are characterized by high intensity and weakly intense n → π*, n → σ* symmetry transitions.
Absorption spectra were recorded in the range from 190 to 760 nm with a step of 1 nm using an SF 2000 automatic electronic spectrometer, and the results were displayed on a computer via ADC. The spectra of individual compounds were taken from the database [13–14].
Subsequently, the calculation was performed on the energy scale of the spectrum.
By processing the data of spectroscopy and calculations by extrapolating the fundamental absorption band using the least square method, the statistical relationships of and IACF were studied. The established dependences for the semiconductors of a number of anthraquinones (Fig. 2 a) and oxypyrenes (Fig. 2 b) have the form:
, (6)
where the constant D1 characterizes the bandgap width of photoconductivity in the absence of autocorrelation of electronic states (IA = 0), the constant D2 reflects a decrease in the bandgap width of photoconductivity with increasing correlation energy of electron repulsion. The values of D1 and D2 for a number of anthraquinones and hydroxypyrenes, as well as calculations of statistical errors, are given in Table. 1.
According to the results of the experiment, for anthraquinones is in the range 1.31–1.43 eV, and for oxypyrenes, respectively, 1.40–1.48 eV. The obtained dependence is statistically substantiated: thus, the determination coefficient R2 is in the range from 0.72 to 0.89, the average relative error is in the range from 0.44 to 1.16%.
As an example, the values of organic semiconductors were determined: 1-dimethylamino 2,3,4-trifluororantraquinone and 11-hydroxybenzo[b]pyrene. The determination was made at the edge of the fundamental band of the absorption spectrum and according to dependence (6) (Table 2). It follows from Table 2 that the average relative error in determining the bandgap width of photoconductivity of organic semiconductors from dependence (6) in comparison with the optical method along the edge of the fundamental band is 6.57%. Therefore, the proposed method for determining the bandgap width of photoconductivity gives adequate results in comparison with the known analogue.
Thus, it is possible to determine the bandgap width of photoconductivity directly from the spectrum by the IACF.
CONCLUSIONS
During the experimental study of optical spectra in the visible and UV ranges for organic heteroatomic semiconductors of the anthraquinone and oxypyrene series, an effect was established that relates the bandgap width of photoconductivity to the integral parameter of the autocorrelational function of the absorption spectrum, which characterizes the interaction of excited electronic states.
The established regularities make it possible to estimate the bandgap width of photoconductivity of organic semiconductors of anthraquinone and oxypyrene series by the integral parameter of autocorrelational function of optical absorption spectra in the UV and visible regions with an accuracy of ±(0.01–0.02) eV sufficient for practical applications. Thus, providing the correct information on the width of the conduction band in organic semiconductors without quantum calculations and separation of spectral bands using the Fourier transform.
The results obtained are intended for use in semiconductor research for the creation of photoelectronic converters, as well as in the development of quantum generators.
The idea of the experiment belongs to M. Dolomatov, schematic design and processing of the results was made by K. Latypov.
REFERENCE
YUrenev P. V., SHCHerbinin A. V., Stepanov N. F. Primenimost’ metodov TD–DFT dlya rascheta elektronnogo spektra pogloshcheniya geksaaminoruteniya (p) v vodnom rastvore. ZHurnal fizicheskoj himii. 2010; 84(1): 44–48.
Bodnar I. V. On the band gap of Cu2ZnSn(S[x]Se[1-x]). Semiconductors. 2015;49: 1145–1148.doi:10.1134 / S1063782615090079.
Simon J., Andre J.-J. Molecular Semiconductors: Photoelectrical Properties and Solar Cells / 1-st ed. – Berlin, Heidelberg, New York, Tokio: Springer-Verlag. 1985.
Vodzinskij V. YU. Organicheskie poluprovodniki / Uchebnoe posobie. – N. Novgorod: NGTU im. R. E. Alekseeva. 2015.
Fajn V. YA. 9, 10-antrahinony i ih primenenie. – M.: Centr fotohimii RAN. 1999.
Tihonov V. I. Statisticheskaya radiofizika. – M.: Radio i svyaz’, 1982.
Rytov S. M. Vvedenie v statisticheskuyu radiofiziku / ch. 1. Sluchajnye processy. – M.: Nauka. 1976.
SHmidt V. Opticheskaya spektroskopiya dlya himikov i biologov. – M.: Tekhnosfera. 2007; 189–194.
Leon W., Couch I. Digital and Analog Communications Systems. 6 ed. – New Jersey: Prentice Hall. 2001; 406–409.
Dolomatov M. YU., Kovaleva E. A. Avtokorrelyacionnyj analiz spektrov pogloshcheniya elektromagnitnogo izlucheniya molekulami policiklicheskih soedinenij v petagercevoj oblasti. Elektromagnitnye volny i elektronnye sistemy. 2016; 21(9): 20–24.
Dolomatov M. YU., Latypov K. F. Opredelenie potenciala ionizacii geterociklicheskih molekul po opticheskim spektram pogloshcheniya elektromagnitnogo izlucheniya v vidimoj i UF oblasti. Fotonika. 2017; 4: 78–82.
Dolomatov M. YU., Latypov K. F. Primenenie metodov statisticheskoj radiofiziki dlya ocenki potencialov ionizacii i srodstva k elektronu molekul po spektram pogloshcheniya elektromagnitnogo izlucheniya v petagercevoj oblasti. Elektromagnitnye volny i elektronnye sistemy. 2017; 22(2):54–60.
Koptyug V. A. Atlas spektrov aromaticheskih i geterociklicheskih soedinenij. Vypusk 13. Spektry pogloshcheniya proizvodnyh antrahinona 9,10 v infrakrasnoj, ul’trafioletovoj i vidimoj oblastyah. Novosibirsk: IOH; NIC MS, 1977.
Bol’shakov G. F., Vatago V. S., Agrest F. B. Ul’tra-fioletovye spektry geteroorganicheskih soedinenij. – L: Himiya, 1969.
ABOUT AUTHORS
Latypov Kamil Faridovich, graduate student, kamil-latipov@rambler.ru, Bashkir State University, www.bashedu.ru, Ufa, Russia
ORCID: 0000-0003-1581-662X
Dolmatov Michel Yurievich, Dr. of Chemical Sciences, dolmatov@gmail.com, Башкирский Bashkir State University, www.bashedu.ru, Ufa State Petroleum Technological University, http://rusoil.net, Ufa, Russia
ORCID: 0000-0003-2677-6993
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