RU2641504C1 - Method for manufacturing photodetector with limited range of spectral sensitivity based on array of zinc oxide nanorods - Google Patents

Abstract

FIELD: nanotechnology.SUBSTANCE: invention relates to optoelectronic devices, in particular to nanotechnologies of solar-blind near-ultraviolet radiation (NUVR) photodetectors based on 1D nanostructured zinc oxide. The method is carried out by using cathodic pulsed electrochemical deposition of water nitrate electrolyte at 55-65°C for 60 minutes on a high-conductive NUVR-transparent fixed substrate of array of base-fusing ZnO nanorods with an average length of 0.65 mcm and an average diameter of unfused sections near the upper ends of 0.30 mcm, subsequent thermal vacuum metallization at an angle to the vertical thin-filmed aluminium through the shadow aluminium mask of the upper ends of ZnO nanorods and high-conductive substrate surface outside their array, forming high-conductive epoxy contact layers on top of the metallised areas, glueing of flexible copper wire ends by epoxy high-conductive glue to the contact layers and annealing of this construction in air at 250°C for 300 s. This method for manufacturing a photodetector is easy to implement and allows to obtain a photodetector with a spectral sensitivity of about 532 at U=1 in the wavelength range of 365-370 nm, and with a cutoff time of 42 seconds, as well as with almost total absence of photosensitivity at λ>380 nm.EFFECT: improving spectral sensitivity of solar-blind photodetector to near-ultraviolet radiation and reducing its cutoff time, simplifying the manufacture technology of such photodetector, reducing its energy consumption and increasing the level of environmental friendliness, excluding the need to use platinum, gold, palladium, indium, graphene in the structure elements of the specified device.7 cl, 9 dwg

Description

The invention relates to optoelectronic devices, in particular to the nanotechnology of sun-blind near-ultraviolet photodetectors (BUFI) based on 1D nanostructured zinc oxide that does not contain inaccessible or expensive materials.

A known method of producing vertically oriented arrays of zinc oxide nanorods by magnetron sputtering (Pat. CN 100517771 (C) of the People's Republic of China, IPC H01L 31/18. Declared November 20, 2007; publ. July 22, 2009) with subsequent application of aluminum layers for use as sensors ultraviolet (UV). This method of obtaining UV sensors includes the following steps: washing and drying the substrate; placing the substrate (a substrate of quartz or sapphire) in a vacuum chamber with a residual pressure of 0.1 MPa so that it is parallel to ceramic targets (ITO or ZnO with a purity of 99.999%) and placed at a distance of 7 cm; feeding oxygen and argon into the chamber in a ratio of 1: 2 to a pressure of 1-1.5 Pa; then sequentially spraying the ITO and ZnO layers. The ITO film thickness in this case is 150-200 nm, and the ZnO film thickness is 600 nm. Then the sample is placed in a quartz furnace in an atmosphere of high-purity oxygen and slowly heated to 400 ° C and maintained at this temperature for one hour. The annealed sample is washed in a 20% NH ₄ Cl solution, and then aluminum layers 200 nm thick are deposited on the ZnO surface.

The disadvantages of this method are related to the fact that its implementation requires very expensive very clean materials. Also, this method requires maintaining a strict atmosphere in the spraying chamber, which is extremely difficult to implement, and non-compliance with these parameters will lead to a change in the morphology of the film and a change in the operational parameters of the instrument structure. The thermal spraying method is an uneven application method with a characteristic maximum in the center of the substrate, which makes it possible to cover areas of not more than 45 × 45 mm with this arrangement in order to achieve uniformity of +/- 5%.

Another known method for producing an array of zinc oxide nanorods with a diameter of 40 nm and a length of 1 μm for use as an LED, field effect transistor, photodetector, etc. is described in US patent (US Pat. US 2006/0189018 A1, IPC H01L 21/00; H01L 33 / 00. Declared June 25, 2004; Published on August 24, 2006). The method for producing nanodevices is based on the production of zinc oxide by decomposition of organic zinc precursors (Zn (CH ₃ ) ₂ , Zn (C ₂ H ₅ ) ₂ , Zn (CH ₃ COO) ₂ * H ₂ O, Zn (CH ₃ COO) ₂ , Zn (C ₅ H ₇ O ₂ ) ₂ , etc.) in an atmosphere containing oxygen: O ₂ , O ₃ , NO ₂ , H ₂ O (steam), CO ₂ , C ₄ H ₈ O, and t .d. As a result, pairs of zinc and oxygen precursor (or oxygen-containing compounds) coming into contact with a p-type semiconductor formed as a thin film on the surface of the substrate at a temperature in the range of 400-700 ° C and a pressure of 0.1-10 mm Hg . form ZnO nanorods.

The main disadvantage of this method is the low productivity and high consumption of precursors due to their decomposition on the heating elements and chamber walls, which is extremely inefficient.

Closest to the claimed invention is a method of manufacturing a near-ultraviolet radiation photodetector (BUFI) with a photoresistive two-electrode structure containing an n-type semiconductor nanostructured ZnO layer in the form of an array of zinc oxide nanorods (MHC-ZnO) and two ohmic contacts (Zhang N., Babichev AV, Jacopin G., Lavenus P., Julien FH, Egorov A.Yu., Zhang J., Pauporte T., Tchernycheva M. Characterization and modeling of a ZnO nanowire ultraviolet photodetector with graphene transparent contact // J. Appl. Phys . - 2013. - V. 114. - P. 234505-1234505-9), therefore, this method is adopted as a prototype. The known method includes:

1) the use of a glass substrate with a highly conductive one-sided coating of fluorine-doped tin oxide (SnO ₂ : F), referred to in the current terminology as FTO and having a surface resistance of R _KV = 10 Ω / square;

2) growing MHC-ZnO over FTO by cathodic potentiostatic electrochemical deposition (PECO) in an aqueous electrolyte pumped with molecular oxygen with an initial pH of 5.5, containing 0.2 mM ZnCl ₂ and 0.1 M KCl, at a cathode voltage (FTO) relative to the saturated silver chloride electrode Comparison (NHSSES) U _К = -1.0 V, electrolyte temperature Т _Э = (85 ± 0.2) ° С, substrate rotation with a constant speed ω = 5 Hz for a time τ _В - 45 min;

3) subsequent washing of the substrate with grown MHC-ZnO in deionized water, drying in air and annealing in air (in order to reduce the residual concentration of donor centers) at a temperature of T _O = 400 ° C for a time τ _O = 1 hour;

4) spin-on filling by the MHC-ZnO free space between nanowires with silsesquioxane hydrogen and its subsequent conversion to SiO _X by annealing at 400 ° C for 1 hour in a stream of N ₂ ;

5) reactive ion etching with the participation of CF _{4 the} upper part of the SiO _X layer until the ends of the MHH-ZnO nanowires are exposed;

6) applying by the method of “wet transfer” to one of the square sections of the surface of MHC-ZnO with an area of 25 mm ^{2 a} graphene transparent to BUFI 4 monolayers thick (previously grown by gas-phase chemical deposition on a Si / SiO ₂ / Ni substrate and separated from it by etching Ni in a solution of FeCl ₃ ) followed by natural drying in air and annealing the sample at 300 ° C in a nitrogen medium;

7) fabrication on top of graphene by electron beam evaporation and lithography techniques of a rectangular “ring” Ti / Au two-layer metal electrode with a thickness of 10 and 150 nm, respectively, covering a slightly smaller area with a rectangular window in the center to allow the BUFI to penetrate through this window into the corresponding MHC region -ZnO;

8) fabrication by similar methods on top of the exposed ends of the MHC-ZnO nanowires spaced apart from graphene, a second continuous rectangular two-layer Ti / Au electrode, forming a rectangular slot gap with the first electrode;

9) attaching flexible wire leads to metal electrodes.

According to the results of structural studies, MHC-ZnO consisted of nanowires with average lengths and diameters of 1 μm and 150 nm, respectively, with an average surface density of nanowires of 10 nanowires / μm ² . Photoluminescent studies revealed the presence of a strong emission peak with a maximum at 380 nm (about 3.26 eV) and a half-width of 130 meV, as well as weak (ten times less intense) yellow-green luminescence in the region of 600 nm (about 2.07 eV), associated with donor centers by oxygen vacancies and other structural defects in ZnO nanowires. As shown electrooptical studies of such devices, if the generated ultraviolet LED BUFI _BUFI with λ = 357 nm and P = _F * 8.5 mW / cm ² under steady photocurrent U = 1 V = _F I was 9.9 mA, and the initial dark current I _T = 3.9 mA. This corresponds to a very low spectral sensitivity (multiplicity of current changes under the influence of the BUFI) - K = I _Ф / I _Т ≈ 2.5, which, apparently, is due to the high residual concentration of donor centers in ZnO nanowires. Response time is the low frequency impacts BUFI was ≈80 _TCI τ c, and cutoff time - τ ≈240 _ots s, which is approximately 4 times the practicality.

Thus, the BUFI photodetector manufactured in a known manner at U _K = -1.0 V provides an appropriate level of the stationary value of the photocurrent, but is characterized by an unacceptably low rate of change in current under the influence of the BUFI, increased cut-off time, partial sensitivity in the visible yellow-green region of the spectrum, which is quite energy-consuming, a very complex and expensive technology for industrial manufacturing using gold, graphene and photolithography.

The objective of the invention is the manufacture of selectively sensitive solar-blind photodetector BUFI based on the MNS-ZnO array, which can significantly increase spectral sensitivity under the influence of BUFI, reduce the cut-off time, significantly simplify the manufacturing technology of such a photo detector, reduce its energy consumption, eliminate the need to use platinum, gold, palladium, indium, graphene, electron beam evaporation, reactive ion etching and photolithography.

The problem is solved by using pulsed electrochemical deposition (PEC), in which an n-type ZnO semiconductor nanostructured layer is formed in the form of MHC-ZnO, and the thermal vacuum deposition of aluminum contacts is performed at an angle of no more than 35 ° to the substrate. This method includes the following steps:

1) the use of a one-sidedly coated FTO layer (with a resistance of 7-10 Ohm / square) transparent to a BUFI glass substrate, subjected to complex liquid-phase chemical cleaning (in perchlorethylene, sulfuric acid and deionized water in ultrasound, in isopropyl alcohol vapors) from possible pollution of organic and inorganic nature;

2) cathodic pulsed electrochemical deposition of MHC-ZnO with nanorods fused at the base with a length of less than 1 μm on a part of the back side of a fixed substrate with an FTO layer at a temperature of 60 +/- 5 ° C and a process duration of up to 1 hour in which is not mechanically stirred and not sparged with any either gases of an aqueous nitrate electrolyte containing Zn (NO ₃ ) ₂ and NaNO ₃ ;

3) subsequent washing of the substrate with MHC-ZnO in deionized water and drying in a stream of warm air;

4) thermal vacuum oblique deposition, at an angle of no more than 35 ° to the surface of the substrate, of the rear aluminum microcontacts at the upper ends of the nanorods and over the FTO outside the MHC-ZnO through the corresponding shadow mask made of aluminum with two rectangular windows;

5) switching the rear aluminum microcontacts on the upper ends of the nanorods with a highly conductive viscous epoxy adhesive, applying a layer of this adhesive over the aluminum contact to the FTO and gluing flexible wire leads to the switching rear highly conductive epoxy contact, as well as to the highly conductive epoxy layer on the aluminum contact to the FTO;

6) annealing the obtained device structure with MHC-ZnO in a thermostat in air at a temperature of 245-255 ° C for a duration of 270 s to 330 s and its subsequent spontaneous cooling together with the thermostat to room temperature.

The essence of the proposed technical solution is that a new method of manufacturing a selectively sensitive solar-blind photodetector BUFI with a photoresistive two-electrode structure containing an n-type semiconductor nanostructured ZnO layer in the form of MHC-ZnO and two ohmic contacts has significant advantages compared to the described in the prototype for a number of important results achieved with its use:

1) in contrast to the cathode PECO used in the prototype for growing MHC-ZnO, cathodic pulsed electrochemical deposition, due to the specifics of the corresponding electrochemical processes and the possibility of more flexible control due to the purposeful variation of the amplitude and time parameters of voltage pulses in the electrochemical cell between the conducting the substrate (cathode) on which the MHC-ZnO are formed, and the counter electrode, allows for the production of MHC-ZnO with optimal for the photodetector BUF structure and properties at significantly lower energy consumption as in the cultivation step and the subsequent annealing in air;

2) due to this, when such a photodetector is irradiated from the frontal surface of the substrate, it exhibits approximately two and a half orders of magnitude higher spectral sensitivity to the BUFI in the range 365-370 nm and a complete absence of photosensitivity at λ> 380 nm and a decrease of more than 5 times cutoffs;

3) accented advantages are realized without the use of expensive platinum, gold, palladium, indium and graphene in the structural elements of the photodetector, as well as without the use of electron beam evaporation, reactive ion etching and photolithography, which significantly complicate the technology for the industrial manufacture of such devices.

The essence of the invention is illustrated by drawings, where

in FIG. 1 schematically depicts a General view of the photodetector obtained by the present method and consisting of: 1 - transparent to BUFI glass substrate; 2 - a highly conductive FTO layer with a surface resistance of 7-10 Ohms / square; 3 - an array of ZnO nanorods fused at the bases with an average length of 0.65 μm and a diameter of non-fused sections near their vertices of 0.30 μm; 4 - film aluminum ohmic microcontacts to the upper ends of these nanorods and film aluminum contact 9 to the FTO layer, which in turn forms an ohmic contact with the bases of intergrown ZnO nanorods; 5 - layer of a highly conductive epoxy composition, switching aluminum microcontacts at the upper ends of the nanorods, and a similar layer 8, covering a solid aluminum contact 9; 6 - flexible wire output glued with a highly conductive epoxy adhesive to layer 5; 7 - flexible wire output glued with a highly conductive epoxy adhesive to layer 8;

in FIG. Figure 2 shows a plot of voltage pulses U _K between a cathode (a working electrode, which is an FTO layer on a glass substrate) and a saturated silver-silver reference electrode, corresponding to the cathodic pulsed electrochemical deposition of an array of ZnO nanorods onto an FTO layer in a three-electrode electrochemical cell during the formation of MHC-ZnO, where, according to generally accepted terminology: U _ON = -1.4 V - the maximum absolute value of U _K , U _OFF = -0.8 V - the minimum absolute value of U _K , τ _И = 0.3 s - pulse duration U _ON ; τ _C = 0.2 s - pulse duration U _OFF ; the indicated time parameters correspond to a duty cycle of 0.6 and a frequency of f = 2 Hz;

in FIG. 3a, b show the results of studies semicontact by atomic force microscopy (AFM) by setting "NanoLaboratory Integra Prima NT-MDT", typical test samples arrays nanorods ZnO, deposited under conditions similar realizable in the manufacture considered photodetector, wherein: a - 3D - image of an array of ZnO nanorods; b - the surface profile of this array in an arbitrarily selected direction of rectilinear movement of the cantilever console above it, from which the average lengths of ZnO nanorods indicated above and the diameter of their non-fused sections near the vertices follow;

) при фокусировке по Брэггу-Брентано (θ-2θ) дифрактограмма, типичная для тестовых образцов массивов наностержней ZnO, осажденных в условиях, аналогичных реализуемым при изготовлении рассматриваемого фотодетектора, содержащая информацию о их кристаллической структуре и текстуре (звездочкой обозначены максимумы, принадлежащие слою FTO);in FIG. Figure 4 shows the DRON-4 X-ray diffractometer obtained in NiKα radiation (wavelength λ _NiKα = 1.65784

) during Bragg-Brentano focusing (θ-2θ), a diffraction pattern typical of test samples of arrays of ZnO nanorods deposited under conditions similar to those realized in the manufacture of the photodetector under consideration containing information on their crystal structure and texture (asterisks indicate the maxima belonging to the FTO layer) ;

in FIG. Figure 5 shows the photoluminescence spectrum obtained using a LabRam HR800 spectrometer in the geometry of backscattering at room temperature, typical of test samples of ZnO nanorod arrays deposited under conditions similar to those realized in the manufacture of the photodetector under consideration, which contains information about their electronic energy structure, as well as possible the ratio of their spectral sensitivity in the near ultraviolet and visible regions of the spectrum;

in FIG. Figure 6 shows a method for measuring the dynamic current – voltage (I – V) characteristics of the photodetector under consideration using an industrial meter of semiconductor devices (STI) type L2-56 when the photodetector is irradiated from the BUFI glass side of the corresponding LED (light dynamic I – V characteristic), which is also suitable and was used to measure dynamic light I – V characteristics of a photodetector during its LED irradiation with radiation from the visible region of the spectrum or in the absence of any irradiation (dark dynamic I – V characteristic);

in FIG. 7a and b shows the dark (no irradiation) and light (when irradiated with stationary BUFI 365≤λ _BUFI ≤370 nm and a power density on the photodetector surface of the glass substrate P * _P = 0.53 W / cm ²⁾ dynamic CVC considered photodetector measured the above method (see Fig. 6);

in FIG. Figure 8 shows a method for obtaining oscillograms of the photocurrent I _{Ф of the} considered photodetector — the current flowing in the photodetector with resistance R _Ф when it is irradiated with a stream of rectangular pulses BUFI and in the measuring circuit to which the photodetector is connected, where: 1 - photodetector; 2 - a stream of rectangular pulses BUFI with 365≤λ _BUFI ≤370 nm and the amplitude of the specific power Р _Ф * = 0.53 W / cm ² on the photodetector surface of the glass substrate, having the shape of a meander with a duty cycle S _u = 2 and pulse duration τ _u = 312 s ; 3 - source HY3020MR of stabilized constant voltage variable in 0.1 V increments; 4 - resistor with active resistance R _a << R _Ф ; 5 - DSO RIGOL DS1064 B to detect the voltage U _a resistor 4, by which the value I _F is determined by using the relationship I _F = U _a / R _a; 6 - multimeter MS8050, connected in parallel to the photodetector as a voltmeter for measuring the voltage U on the photodetector;

in FIG. 9 shows a fragment of the waveform of the photocurrent I _F consideration photodetector at a voltage on the photodetector U = 1 V, which allows to evaluate the degree of reproducibility indicating BUFI such device in a mode of the spectral sensitivity corresponding to said voltage and to determine its response time τ _TCI during which the detected photodetector signal increases from zero when the BUFI pulse arrives to 0.63 of its maximum value corresponding to saturation under the influence of this pulse, and also e cutoff time τ _UTS, during which the signal detected by the photodetector decreases from said maximum value to its value after 0.37 BUFI pulse cutoff.

Example 1. The manufacture of a photodetector with a limited range of spectral sensitivity in the field of BUFI based on MHC-ZnO, a general view of which is schematically shown in FIG. 1, was carried out using a rectangular transparent for BUFI substrate coated on one side with an FTO layer with a resistance of 7-10 Ohms / square. Then these substrates were subjected to complex chemical cleaning: in perchlorethylene in ultrasound for 20 minutes; in pairs of isopropyl alcohol for 1 hour; rinsing in deionized water; purification in concentrated sulfuric acid for 30 seconds; washing in an ultrasonic bath with deionized water and drying in a stream of warm air.

Deposition on the washed glass substrate was carried out in a thermostated three-electrode electrochemical cell with an aqueous nitrate electrolyte containing 0.05 M Zn (NO ₃ ) ₂ and 0.1 M NaNO ₃ . The temperature throughout the entire process of formation of MHC-ZnO was maintained in the range of 55-65 ° C, the formation time of 60 minutes. A platinum coil was used as a counter electrode. The reference electrode was a silver chloride saturated standard electrode. Rectangular voltage pulses (according to Fig. 2) with a frequency of ƒ = 2 Hz were applied to the working electrode. In this case, U _ON = -1.4 V and U _OFF = -0.8 V were supplied for 0.3 and 0.2 seconds, respectively; the number of pulses was 7200.

Then, in a vacuum installation, at a residual gas pressure of 0.1-1 MPa, a thermal vacuum deposition of a vapor stream of aluminum atoms onto the upper ends of ZnO nanorods and over the FTO layer outside the specified array was carried out through an aluminum shadow mask on a substrate surface partially covered with an array of ZnO nanorods. The substrate with the mask was located at an angle of 30 ° normal to the vertical above the evaporator, which avoids complete metal enveloping of ZnO nanorods. The deposition of aluminum is carried out until the formation of a layer with a thickness of 80-100 nm. Then, the rear aluminum microcontacts at the upper ends of the ZnO nanorods are interconnected by applying a continuous layer of highly conductive viscous epoxy adhesive to the outer surface, as shown in FIG. 1. Connecting one of the flexible copper wire leads of the photodetector simultaneously to all with aluminum microcontacts, which after hardening forms a single rear highly conductive epoxy contact of the photodetector (position 5 in Fig. 1). A similar operation was performed to fabricate a highly conductive epoxy contact (key 8 in FIG. 1) over an aluminum contact (key 9 in FIG. 1) deposited on the FTO layer. The connection of external flexible copper wire leads with a diameter of 0.1 mm each (positions 6 and 7 in Fig. 1) to these two highly conductive epoxy contacts (positions 5 and 8 in Fig. 1) was carried out by gluing them with a similar highly conductive epoxy glue followed by hardening.

The final operation in the manufacture of the photodetector was its annealing in air with a duration of τ _O = 300 s at a temperature T _O = 250 +/- 5 ° С.

Performed by the method shown in FIG. 6, the measurements shown in FIG. 7 dynamic CVC photodetector consideration shows that when irradiated with a stationary BUFI 365≤λ _BUFI ≤370 nm and a power density on the photodetector surface of the glass substrate P * _P = 0.53 W / cm ² results in the maximum spectral sensitivity at U = 1 to _F photocurrent I = 5.0 mA, and in the absence of irradiation at U = 1 in its dark current is I _T = 9.4 mA (FIG. 7a), which corresponds to the spectral sensitivity S≈532.

Thus, at U = 1 V and the influence of the BUFI, the spectral sensitivity of the photodetector manufactured by the claimed method is approximately 213 times higher than the spectral sensitivity of the photodetector made according to the prototype. However, as was established by the dynamic light CVC method, the photodetector manufactured by the claimed method, at λ> 380 nm, the spectral sensitivity was practically absent.

According to the waveform shown in FIG. 9, after annealing photodetector made by the claimed method, it RTT _TCI τ = 100 s, which is slightly different from the prototype _TCI τ and τ _ots cutoff time = 42 s, which is about 5.7 times smaller than τ _ots prototype. In addition, from the accented waveform, good reproducibility of the monostable switching process of the photodetector made by the claimed method follows between a stable low-conductive state in the absence of irradiation and a metastable high-conductive state during irradiation with near ultraviolet radiation, which indicates the proper stability of the operation of such a photodetector.

The reproducibility of the above described effectiveness of the claimed invention of a photodetector with a limited range of spectral sensitivity based on an array of zinc oxide nanorods has been tested in a series of experiments.

Thus, the use of the inventive method makes it possible to produce a selectively sensitive solar-blind near-ultraviolet light photodetector based on an array of ZnO nanorods with significantly increased spectral sensitivity and photocurrent at a voltage of 1 V, as well as with significantly reduced cut-off time, using a fairly simple, low-energy, environmentally friendly and easily adaptable manufacturing technology for industrial applications, eliminating the need to use the use of expensive platinum, gold, palladium, indium, graphene, as well as complicated and expensive methods of electron beam evaporation, reactive ion etching and photolithography in the design elements of the photodetector.

Claims (7)

1. A method of manufacturing a photodetector with a limited spectral sensitivity range based on an array of zinc oxide nanorods, comprising cathodic electrochemical deposition of an array of ZnO nanorods on a part of an area of a highly conductive transparent substrate for near ultraviolet radiation, which is one of the ohmic contacts to the base of the ZnO nanorod array that mates with it, deposition the second layered ohmic contact on the upper ends of the ZnO nanorods of this array, applying a layered conductive contact site on a highly conductive substrate outside the array of ZnO nanorods, galvanic coupling of flexible wire leads with a layered ohmic contact at the upper ends of the ZnO nanorods and with a conductive contact pad outside the array of ZnO nanorods, characterized in that the production of an array of ZnO nanorods under the conditions of intergrowth neighboring nanorods, carried out by its cathodic pulsed electrochemical deposition on a part of the surface of a fixed substrate, previously chemically pure searched in an ultrasonic bath for possible contaminants of organic and inorganic nature, washed in deionized water and dried in a stream of warm air; applying a layered ohmic contact to the upper ends of the ZnO nanorods of this array and applying a layered conductive contact pad to a highly conductive substrate is performed by thermal vacuum metallization of the corresponding regions with aluminum through a shadow mask and the subsequent formation of highly conductive epoxy contact layers on top of the metallized regions; galvanic coupling of flexible wire leads with a layered ohmic contact at the upper ends of ZnO nanorods and with a conductive contact pad outside the array of ZnO nanorods is carried out by gluing high-conductive epoxy adhesive of flexible wire leads to highly conductive epoxy layers previously formed in these areas; the final operation is annealing this structure in air. 2. The method according to p. 1, characterized in that the highly conductive transparent for near ultraviolet radiation substrate is made of a glass plate NSG TEC ™ A7 from Pilkington with a coated FTO layer with a thickness of 450-550 nm and a specific resistance of 7-10 Ohms / square. 3. The method according to p. 1, characterized in that the cathodic pulsed electrochemical deposition of an array of ZnO nanorods with fused bases is carried out in a standard glass thermostatic three-electrode electrochemical cell with an aqueous solution of zinc nitrate and sodium nitrate not stirred and not sparged by any gases. 4. The method according to p. 1, characterized in that the cathodic pulsed electrochemical deposition of an array of ZnO nanorods with fused bases is carried out with rectangular voltage pulses between the cathode substrate and the platinum anode with a frequency of 2 Hz and a fill factor of 0.6. 5. The method according to p. 1, characterized in that the oxidation and reduction potentials are taken respectively minus 1.4 V and minus 0.8 V relative to the silver chloride reference electrode. 6. The method according to p. 1, characterized in that the thermal vacuum metallization of the upper ends of ZnO nanorods with aluminum is performed at an angle of 30 ° to the vertical and above the evaporator at a residual gas pressure of 0.1 to 1 MPa. 7. The method according to p. 1, characterized in that the flexible leads are made of copper wire with a diameter of 0.08-0.10 mm

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