ES2572131B1 - Method of obtaining thin layers of photoelectric material with perovskite type structure and layers thus obtained - Google Patents

Abstract

Method of obtaining thin layers of photovoltaic material with perovskite type structure by means of the thermal evaporation technique from a single source. # By the method described here, it is possible to obtain thin layers of organic-inorganic hybrid perovskites by means of the instantaneous evaporation technique obtaining uniform thin layers and high crystallinity. These layers have been tested on flat photovoltaic devices, showing high energy efficiency.

Description

Method of obtaining thin layers of photoelectric material with perovskite type structure and layers thus obtained

Technical field

The present invention relates to the obtaining of layers of organic-inorganic hybrid semiconductor material of the perovskite type useful in opto-electronic devices by means of the instantaneous evaporation technique as well as to the asl layers obtained and to opto-electronic devices containing them.

State of the art

10 Opto-electronic devices such as photoelectric cells or solar cells, among others, are devices that transform light energy into electrical energy. Its operation is based on the photovoltaic effect, and one of its constituent elements is a material capable of absorbing photons and generating an electric current. In recent years they have aroused great interest as photovoltaic materials certain hybrid materials

15 organic-inorganic, and in particular the materials with structure of type ~ perovskita ~ (hereinafter simply called Mperovskitas ~) based on organometallic halides with aliphatic or aromatic ammonium cations and divalent metals, due to their high mobility of loads and their easy deposition even with dissolution based methods. More recently, inorganic-organic hybrid perovskites

20 three-dimensional with formula RMX3, where R is the methylammonium ion (CH3NH3 +) or the Ion formamidinium (HC (NH2) 2+), M is Pb2 + or Sn2 + and X is CI-, Sr "or 1-, they have been used as thin-layer light collectors in solar cells, leading to unexpected and remarkable values in energy conversion efficiencies (PCEs), the lead iodide methylammonium perovskite (CH3NH3Pbb) has been widely used as

25 light collector in solar cells. To this end, perovskite is disposed in the form of a thin layer on a metal sheet using different deposition techniques from dissolution, among which are deposition in a single step using a mixture of solvents, sequential deposition or liquid-vapor assisted deposition. . PCE values of up to 19.3% have been achieved.

30 Recently, within this perspective, the use of the dual vapor deposition technique has been proposed as an alternative in the preparation of thin layers of CH3NH3Pbh for photovohalic applications. These layers have been obtained by simultaneous evaporation of the lead halide in question (Pbb or PbCb) and methylammonium iodide

5

CH3NH31 in a high vacuum chamber. The layers deposited by evaporation are relatively flat and homogeneous, and when they have been used in the structure of solar cells, PCE values of 15.4% have been obtained. The ca-evaporation allows a fairly precise control of the stoichiometry and thickness of the perovskite layers, with the advantage of the high purity of the sublimated materials. In addition, this technique also allows multilayer preparation and is compatible with standard semiconductor processing. However, this process is relatively slow and requires periodic calibrations for proper control of the deposition rate and the relationship between the precursors.

10 .5 ~ O

In US 6,117,498 an alternative method for the deposition of organic-inorganic hybrid materials such as thermal evaporation from a single source (SSTA) is described. According to this document, the material on the one that is going to be evaporated is deposited on a metal and it is taken under vacuum; then a high current is passed through the metal on which the material is located, causing the rapid evaporation of the material, which is deposited finally on the desired substrate because it is at a lower temperature The layer of the hybrid material is formed at a temperature sufficient for the inorganic compound to evaporate without causing the decomposition of the organic material. a great variety of compound semiconductors, obtaining optically active thin layers and pOlicristalinas.This method, however, pres The disadvantage is that the layers obtained are generally too rough for incorporation in opto-electronic devices, which can use multilayers of thicknesses of up to 800 nanometers.

~ 5: 0

Therefore there is still a need to find a method of preparing thin layers of perovskite, in particular of lead halide methylammonium, and more in particular of lead iodide (CH3NH3Pbb) for opto-electronic applications whereby layers are obtained of homogeneous perovskite, with thicknesses between 50 and 500 nm, with a uniform surface and high crystallinity. These thicknesses are necessary when used in photovoltaic devices so that they have a high capacity for solar absorption without inhibiting the transport of loads.

Description of the invention

Summary of the Invention

3

The aforementioned problems have been solved by identifying the inventors that it is possible to overcome the drawbacks of the prior art methods using a method that adequately controls the parameters involved in the deposition of the organic-inorganic or hybrid material layer. its predecessor and in particular controlling the roughness of the layer to be subjected to instantaneous evaporation, so that said roughness is less than 2 micrometers, preferably less than 1 micrometer, and most preferably less than 0.5 micrometers. According to the inventors, when said layer has a roughness within the stipulated limits, the resulting coating has a highly uniform thickness. This causes the heat of the metal sheet to be transferred instantly to all the material, which vaporizes at the same time. The result is a highly homogeneous and crystalline perovskite layer. This method allows to obtain layers with thicknesses greater than 150 nm and RMS roughness (mean square value) of about 20 nm. The layers obtained by this procedure have demonstrated a good functioning in solar cells, reaching a PCE value greater than 12%.

Brief description of the figures

Figure 1 shows a general scheme of the method of obtaining layers of organic-inorganic hybrid semiconductor material of the perovskite type used. The substrate (1) on which the perovskite layer is to be deposited is held vilo within a vacuum chamber (2), held by a first conveyor belt (10) that can enter and exit the vacuum chamber ( 2) through the valves (3). On the other hand, a metal crucible (4) is coated with a perovskite precursor layer using a coater (5), and the crucible with the perovskite precursor layer (6) is transported by a second conveyor belt (11) to a heater (7) where the layer dries and then follows the vacuum chamber (2). There, two electrodes (8) (metal blocks of a high conductivity metal such as copper) are connected to the crucible and an electric current is applied

(9) to the circuit, which consequently passes through the metal crucible. This causes a rapid heating of the metal crucible and the instantaneous evaporation of the perovskite film, which is deposited on the substrate (1) because it is at a lower temperature. The metal crucible, already cleaned, is then returned to the coater to start a new cycle, which means that the method described here can work continuously. This evaporation-deposition technique is generally known as instantaneous evaporation or flash evaporation, although it is also sometimes called SSTA (~ Single SOurce thermal ablation "or ~ thermal evaporation from a single source"), in reference to the fact that the material that evaporates instantly comes from a single source. In the present invention it is not desired that the invention be limited to a particular type of instant evaporation technique, but that any of them can be used, as long as it is possible to achieve the desired objective in terms of the characteristics of the layer of resulting perovskite.

Figure 2 shows a scheme of the method of deposition of a thin layer of perovskite by instant evaporation, where the precursor solution has been deposited on the crucible by the meniscus coaling meniscus coating technique ").

Figure 3 (a) shows the X-ray diffraction spectrum of a thin layer of CH3NHJ Pbb obtained according to Example 1.

Figure 3 (b) shows the topography of the layer surface by means of the atomic force microscope (AFM WAtomic Force Microscopt) of the perovskite layer of Example 1.

Figure 4 (a) shows a diagram of the external quantum efficiency (EQE "External Quantum Efficiency") and of the optical absorption in the UV-visible region for an oblenida flat solar cell according to Example 2.

Figure 4 (b) shows the current density versus voltage curve for the solar cell of Example 2.

Figure 5 is a schematic representation of a three-dimensional perovskite structure.

Detailed description of the invention

The present invention relates to a method for producing thin layers of photoactive materials for use in solar cells with perovskite type structure using the instantaneous evaporation technique as a step of the method.

The organic-inorganic hybrid materials are very suitable for this function due to their optoelectronic properties, the high mobility of their loads and their ability to be deposited in the form of a thin layer. Some of the materials that have been widely used for this purpose are inorganic-organic hybrid perovskites, in which one of the cations is organic and the other inorganic. In the present specification, the term "perovskite" refers to the perovskite structure (see schematic representation of a three-dimensional perovskite structure in Fig. 5), and not to the perovskite mineral (CaTi03) as such. Thus, in this report the term "perovskite" encompasses any material that has the same crystalline structure as the titanium oxide calcium mineral called

"perolJskita". In general, the perovskites used here are organic-inorganic hybrid compounds with perovskite structure according to any one of the following general formulas:

M 'MX, AMX,

BMX,

where A and A 'are monovalent organic cations that are independently selected from primary, secondary, tertiary or quaternary ammonium organic compounds, including N-ring and hetero-ring systems, having A and A' independently of 1 to 60 atoms of carbon and 1 to 20 heteroatoms;

B is a divalent organic cation selected from organic ammonium compounds

primary, secondary, tertiary or quaternary, having 1 to 60 carbon atoms and 2

to 20 heteroatoms, and have two positively charged nitrogen atoms;

M is a divalent metal selected from the group consisting of Cu2 +, Ni2 +, C02 +, Fe2 +, Mn2 +, Cr +, Pd2 +, Cd2 +, Ge2 +, Sn2 +, Pb2 +, Eu2 +, and Yb2 +;

N is selected from the group of Bi3 + and Sb3 +, and

the three or four Xs are independently selected from cr, Sr-, 1-, NCS-, CN- and NeO-.

The typical perovskite structure is a three-dimensional (3D) structure such as that shown in Figure 5, of general formula AMX3 • consisting of a three-dimensional network of octahedra of formula M ~ that share the corners, in which the atom M is typically a metal cation and X is an anion, with the appropriate load balance to balance cations A and B. However, in addition to 3D perovskites, layered perovskites can also be formed, called two-dimensional perovskites or 20, which are configured based on extracting a layer of thickness n of the 3D structure of the perovskite along a given crystallographic direction, and alternating those layers with some other modulation layer. Among the possible termination planes, the <100> and <110> 30 planes are the most common. Perovskites oriented according to plane <110> adopt

generally the general formula AnMnX3n + 2, while those oriented according to the plan

<100> adopt various types of general formulas, among which we can find the formulas A n + 1BnX 3n + l and (Bb02) An-1BnO 3n + l, among others. In more preferred embodiments, the perovskites described herein are three-dimensional compounds of the general formula AMX3 • in which A is the methylammonium cation CH3NH3 + or the formamidinium cation HC (NH2) 2+, M is

Pb '· or Sn' · yXes r, Br or er.

Here the term PCE refers to the Energy Conversion Efficiency (pCE MPower Conversian Efficiencies ") and is defined as the performance of the solar cell.

It is known in the art that the characteristics of the perovskite layer have a fundamental role in achieving a high PCE in the resulting solar cell. Therefore, achieving a homogeneous perovskite layer with a uniform surface and high crystallinity is key to obtaining a high yield in solar cells.

Many strategies have been proposed for obtaining perovskite layers from dissolution, for example: one-step deposition, solvent mixing, sequential deposition or liquid-vapor assisted deposition, with additional treatments such as thermal or solvent treatments and solvent drip.

One of the possible physical methods for the deposition of organic-inorganic hybrid materials is instant evaporation or flash evaporation. The objective of this technique is to achieve evaporation or sublimation of the organic and inorganic part at the same time without degrading any of them. For example, when deposition is done with dissolution techniques, the different solubility of organic and inorganic components makes it difficult to find a common solvent. In the case of evaporation techniques, the different evaporation points cause the decomposition of the organic part when sufficient temperature has been reached to achieve evaporation of the inorganic part. A variant of the instantaneous evaporation is the so-called "thermal ablation of a single source ~ or SSTA (from English" Single Source Thermal Ablationft when the material that is

)

subjected to ablation or vaporization comes from a single source. According to this technique, perovskite or its precursors are first deposited on a conductive material, either in solid form, or in liquid form by depositing drops of a solution of perovskite on a melalic crucible. It is possible to start from the perovskite already formed, or from precursors thereof (for example, lead halide (PBb or PbCb) and methylammonium iodide CH3NH31). Since said crucible is subjected to very rapid heating, all deposited material

on the crucible it evaporates instantly and is deposited on any cold surface of the vacuum chamber, and consequently also on the substrate, which is usually placed on top of the crucible. This technique allows the organic part of the perovskite to vaporize without decomposing. In addition, the process is carried out in vacuo, so that a high purity of the perovskite deposited on the target substrate is achieved. A general outline of the complete procedure that includes this stage can be seen in the attached Fig. 1.

As the inventors observed, for small amounts of material deposited on the crucible, this prior art method leads to fairly smooth and thin films, generally with a thickness less than 50 nm. When a larger quantity of material is applied to the crucible, the film deposited on the substrate turns out to be very rough (rms greater than 100 nm) and not suitable for application in solar cells or other sandwich-type opto-electronic devices (OLEDs).

The inventors of the present invention have solved this problem by identifying that, when the film to be subjected to vaporization has a roughness of less than 2 Jlm, more preferably less than 1 Jlm, and most preferably less than 0.5 Jlm, it is possible to obtain layers of perovskite thicker than those of the prior art (thickness greater than 50 nm and up to 800 nm, more preferably between 150 and 500 nm) and exceptionally smooth (roughness <40 nm and typically between 10 and 20 nm). This result was quite unexpected, since what would be expected is that the only parameters that affect the properties of the vaporized film were the amount of material and the evaporation rate, but not the way in which said material was present in the crucible, and in particular the homogeneity of the coating layer. As indicated, the inventors are of the opinion that, when said layer has a uniform thickness and a low roughness, the heat of the metal sheet is instantly transferred to all the material, which vaporizes at the same moment. The result is a homogeneous and highly crystalline perovskite layer, which allows these layers to be obtained with a thickness greater than 150 nm and with a roughness (RMS) of about 20 nm.

Therefore, in a first aspect the invention is directed to a method for forming a film of an organic-inorganic hybrid material on the surface of a substrate (1) comprising the following steps:

a) placing said substrate (1) in a chamber (2);

b) depositing a selected amount of a solution of said organic-inorganic hybrid material or a precursor thereof on a metal sheet (4), which is then dried forming a coating layer on said metal sheet (4);

e) insert the metal sheet (4) with the organic-inorganic hybrid material coating layer or its precursor into the chamber (2), making the vacuum therein, and

d) passing through the metallic sheet (4) an electric current of sufficient intensity to cause the total vaporization of the organic-inorganic hybrid material covering said sheet in a time less than 5 seconds and preferably less than 1 second and the subsequent deposition of an amount of organic-inorganic hybrid material on a surface of the substrate (1),

wherein the coating layer of organic-inorganic hybrid material or a precursor thereof on the sheet (4) which is subjected to vaporization has a roughness of less than 2 ... 1m, preferably less than 1 ... 1m and even more preferably less than 0.5 .1m.

In a second aspect, the invention is directed to the films of organo-organic hybrid material thus obtained, as well as to opto-electronic devices comprising them.

To carry out the coating of the perovskite precursor on the metal sheet it is possible to use different techniques, such as the meniscus coating ("meniscus coating ~) or the sequential vacuum deposition in two stages, among others. The first case is exemplified in the Examples described later in the present specification In the second case, the coating is carried out by placing, in a first stage, several drops of perovskite precursor solution on a first metal sheet, to then be carried out in a second stage the instant evaporation on a second metal sheet, although the inventors prefer the first of both techniques (the meniscus coating) for practical reasons, however the important thing is that the technique used is capable of providing thin layers with high homogeneity , which is determined herein by a roughness of less than 2 f.1m,

more preferably less than 1 f.1m, and most preferably less than 0.5 f.1m. Therefore, the inventors consider that other coating techniques such as spin-coating or other printing techniques would be equally applicable, as long as coating layers of the desired roughness and homogeneity can be achieved with them.

As regards the substrate where the perovskite layer is deposited after said perovskite or its precursor has been subjected to instantaneous evaporation or SSTA, in general said substrate is a conduelor substrate, and preferably a semi-transparent conductive substrate, which It may have been previously coated with other semiconductor materials, whether organic or inorganic, and that is intended to be used as an electrode of an opto-electronic device.

The material deposited according to the method of the invention has been characterized using both optical and morphological methods, revealing a high degree of homogeneity as well as a low roughness. The photovoltaic properties of the thin layer of eH3NH3Pbb have been evaluated in flat heterojunction solar cells using organic charge-carrying layers, obtaining efficiencies above 12%.

Experimental examples

Example 1

Prepare a layer of lead iodide melylammonium perovskila (CH, NH, Pbl,).

The ammonium salt used was methylammonium iodide or MAl (its English name, ~ Methyl Ammonium lodide ") which was synthesized according to the method already published in L. Elgar, P. Gao, Z. Xue, a. Peng , AK Chandiran, B. Líu, MK Nazeeruddin and M. Gratzel, Journal 01 Ihe American Chemical Sociely, 2012, 134, 17396-17399. Then the ammonium salt was dried at 600 e in vacuo for 24 hours, then a solution was prepared 50% by weight of perovskite precursor dissolving Pbb (Sigma Aldrich) and MAl in DMF, with a Pbb: MAI molar ratio of 1: 3. The solution was subsequently deposited on a metal sheet, which in the present example was a sheet of 70x15xO, 05 mm tantalum, using the ~ meniscus coating technique "(Fig. 2 (a». The coating layer was created by placing 80 I, d of the precursor solution under a 1.2 mm thick metal sheet and spread over the tantalum sheet at a speed of 80 mm / s. During deposition, the metal sheet was heated to a temperature of 800 e and once the perovskite layer was formed (when it turns yellow to dark brown, Fig. 2 (b », it was heated at a temperature of 125 ° e for 5 minutes to remove excess solvent The result was a layer of perovskite of methylammonium iodide with a very high homogeneity, which is manifested by a roughness of 20 nm. Next, the tantalum sheet was transferred to the high vacuum chamber and held between two electrodes connected to a high voltage source (Fig. 2 (c.). On the other hand, the substrates on which the material was placed in a sample holder that was at a vertical distance of 10 cm above the evaporation source After establishing a stationary vacuum of 0.1 m bar, a high current (approximately 30A) was passed through the tantalum sheet , causing the complete evaporation of CH3NH3Pbl3 in approximately 5 seconds, although it normally occurred in 1 second or less.The thickness of the resulting layer was controlled by the amount of perovskite deposited on the metal sheet.In Fig 3 (a) it is shown X-ray diffraction (GIXRD) of a 200 nm sample deposited by evaporation.The spectrum suggests a high degree of crystallinity, with peaks at 14.1 °, 28.4 ° and 31.8 ° m confining the formation of the structure tetragonal crest of the perovskite MAPbh. The topography of the surface of the layer was also investigated by atomic force microscopy (AFM, Fig. 3 (b). The layer shows a homogeneous and relatively flat aggregation, with an average roughness (RMS), calculated over an area of 251Jm2 , of 17.6 nm.

Example 2

Preparation of solar cells that integrate a perovskite layer manufactured according to Example 1.

Single-junction solar cells were prepared by integrating a layer of perovskite manufactured according to Example 1 into a multilayer structure of organic semiconductor charge carriers. For this, a crystal coated with indium tin oxide (ITO) was used as a transparent electrode in the lower part of the device. About 80 nm of poly (3,4-ethylenedioxythiophene) doped with poly (styrenesulfonate) (PEDOT: PSS, Heraeus Clevios ™ P VP Al 4083) were deposited on the ITO using the spin-coating technique, and used as an injection layer of holes (HIL). After heating at 150 ° C for 15 minutes, a 20 nm layer of poly (N, N'-bis (4-butylphenyl) - was deposited by spin-coating. N, N'-bis (phenyl) benzidine) (polyTPD, HTL, 1% by weight in chlorobenzene) on the PEDOT layer: PSS and then heated at 180 ° C for 30 sec. The substrate with the two layers already deposited a 200 nm layer of perovskite MAPbl3 was deposited onto the substrate where SSD and polyTPD had previously been placed via SSTA and the device was completed by depositing 80 nm of methyl ester of the spin-coating. (6,6) -phenyl CS1 butyric acid (PCBM) and depositing the bi-layer that will act as a cathode, composed of B, empty a and Ag (10 and 100 nm respectively). The characterization of the device was carried out in a nitrogen box, using a mini solar simulator calibrated by means of a silicon reference sample. Fig. 4 (a) shows the EQE of the device as well as the UV-visible spectrum of the perovskite layer. Optical absorption shows the typical

MAPbb perovskite profile, with wide absorption across the entire spectrum of the

visible up to 800 nm, corresponding to the 1.55 eV optical bandwidth. The EQE

increases in the same wavelength, reaching the maximum value in 73% in the green

(570 nm) and in blue (420-450 nm), as can be seen in the spectrum. the curve of

5 current-voltage density (J-V) characteristic of solar cells is shown in Fig.

4 (b). The device shows only a small hysteresis depending on the direction in the

which voltage is applied, contrary to what is observed in devices based on

deposition by dissolution. The closed circuit current density (JSC), the

Open circuit voltage (VOC) and fill factor (FF) for a typical device are 18.0 10 mAlcm2, 1.07 V and 68%, respectively, reaching an energy conversion efficiency of 12.2%.

Consequently, the previous tests demonstrate that, by controlling the roughness of the perovskite layer or a precursor thereof that it will be subjected to instantaneous evaporation so that it is within a certain range as defined previously in the In the present specification, the resulting coating is a highly homogeneous and crystalline layer of perovskite with a very uniform thickness, which allows obtaining such layers with thicknesses greater than 50 nm and up to 800 nm, preferably between 150 and 500 nm, and roughnesses (RMS ) below 40 nm but typically between 10 and 20 nm These layers have been tested in

20 flat photovoltaic devices, showing high energy efficiency.

Claims (16)

1. A method for forming a film of an organic-inorganic hybrid material with a perovskite type structure on the surface of a substrate (1) comprising the following steps: a) placing said whisper (1) in a chamber (2); b} depositing a selected amount of a solution of said organic-inorganic hybrid material with a perovskite structure or a precursor thereof on a metal sheet (4), which is then dried forming a coating layer on the metal sheet ( 4); e) insert the metal sheet (4) with the organic-inorganic hybrid material coating layer with perovskite type structure or its precursor into the chamber (2), making the vacuum therein, and d) passing through the metallic sheet (4) an electric current of sufficient intensity to cause the total vaporization of the organic-inorganic hybrid material with a perovskite-like structure that covers said sheet in a time of less than 5 seconds and the subsequent deposition of an amount of organic-inorganic hybrid material with perovskite type structure on a substrate surface (1), characterized in that the coating layer of organic hybrid material inorganic with perovskite type structure or a precursor of the same deposited on the sheet (4) that is subjected to vaporization has a roughness of less than 2¡1m.

2.

The method of claim 1, wherein the roughness of the organic-inorganic hybrid material coating layer with perovskite type structure or a precursor thereof deposited on the sheet (4) is less than 1 .1m.

3.

The method of claims 1 or 2, wherein the roughness of the organic-inorganic hybrid material coating layer with perovskite type structure or a precursor thereof deposited on the sheet (4) is less than 0.5. 1m

Four.

The method of any one of the preceding claims wherein the organic-inorganic hybrid material with perovskite structure is a bi-dimensional compound with perovskite structure according to any one of the following general formulas:

AA'MX, AMX, AA'NW <. BMX, where AYA 'are monovalent organic cations that are independently selected from primary, secondary, tertiary or quaternary ammonium organic compounds, including ring systems and N-containing hetero rings, having A and A' independently from 1 to 60 carbon atoms and from 1 to 20 heteroatoms; B is a divalenle organic cation selected from organic compounds of primary, secondary, tertiary or quaternary ammonium, having 1 to 60 carbon atoms and 2 to 20 heteroatoms, and having two positively charged nitrogen atoms; M is a divalent metal selected from the group consisting of Cu2 +, Ni2 +, Co2 +, Fe2 +, Mn2 +, cr +, Pd2 +, Cd2 +, Ge2 +, 8n2 +, Pb2 +, Eu2 +, and Yb2 +; N is selected from the group of Bi3 + and Sb3 +, and the three or four Xs are independently selected from cr, B (, r, NCS-, CN and NCO ·.

5.

The method of claim 4, wherein the organic-inorganic hybrid material is a three-dimensional compound with perovskite structure of the general formula AMXa, wherein A is the methylammonium ion (CH3NH;) or the formamidinium ion (HC (NH,);) , M is Pb2 + or 8n2 + and X is cr, Br-o r.

6.

The method of claim 5, wherein the organic-inorganic hybrid material is lead iodide methylammonium (CH3NH3Pbb) with three-dimensional perovskite structure.

7.

The method of claim 6, wherein the precursor of the inorganic organic hybrid material is a solution of Pbb and methylammonium iodide in a molar ratio.

1: 3 in DMF.

8.

The method of any one of the preceding claims wherein the deposition of the organic-inorganic hybrid material or a precursor thereof on the metal sheet (4) is performed by a technique selected from the group consisting of meniscus coating, deposition in two-stage sequential vacuum, liquid-vapor assisted deposition, or spin-coating.

9.

The method of claim 8, wherein the deposition of the organic-inorganic hybrid material or a precursor thereof on the metal sheet (4) is performed by the meniscus coating technique at a speed of 80 mm / s.

10.

The method of any one of the preceding claims wherein the metal sheet (4) is a metal sheet with high thermal resistance such as tantalum or molybdenum.

eleven.

The method of any one of the preceding claims wherein the electric current that is passed through the metal sheet (4) has an intensity of 30A.

12.

The method of any one of the preceding claims which is a continuous method.

13.

A film of organic-inorganic hybrid material obtained according to the method of any one of the preceding claims 1-12, having a thickness between 150 and 500 nm and an RMS roughness of less than 40 nm.

14.

Opto-electronic device comprising at least one film of organic-inorganic hybrid material according to claim 13.

fifteen.

Opto-electronic device according to claim 14 which is a single junction solar cell.

16.

Opto-electronic device according to claim 15 which is a single junction solar cell further comprising an indium tin oxide (ITO) electrode coated with PEDOT: PSS as a hollow injection layer.