US-12628544-B2 - Method for manufacturing a layer of multi-cation perovskite to form photo-active layer involving slot die coating or a blade coating of wet film, and sweeping of the wet film by flow of dry air or inert gas having specified speed, and application of heat treatment to substrate

US12628544B2US 12628544 B2US12628544 B2US 12628544B2US-12628544-B2

Abstract

A method for manufacturing a multi-cation perovskite layer, including: a) supply of a substrate having a deposition face, b) deposition of a precursor solution including precursors comprising CsX, FAY, PbZ 2 , with X, Y and Z═I, Br, and an FACl additive, the molar ratio of cesium to lead is between approximately 4% and 22%, the molar ratio of FACl relative to lead between 0.1% and 5%, and the perovskite layer has an empirical formula of the type Cs x FA (1−x+w) Pb(I y Br (1−y) ) 3 with x between 0.04 and 0.22, y between 0 and 1 and w between 0.001 and 0.05, c) sweeping of the wet film by an inert gas to crystallize the perovskite layer, and heat treatment so that the deposition face has a temperature ranging from about 25° C. to 80° C. C at least during step b).

Inventors

Matthieu MANCEAU
Noëlla Lemaitre
Stéphane Cros
Mathilde FIEVEZ

Assignees

COMMISSARIAT À L'ENERGIE ATOMIQUE ET AUX ÉNERGIES ALTERNATIVES

Dates

Publication Date: 20260512
Application Date: 20230421
Priority Date: 20220421

Claims (11)

1 . A method for manufacturing a layer of perovskite with multi-cations, with a view to form a photo-active layer, the method comprising the steps of: a) suppling a substrate having a deposition face, b) depositing a precursor solution comprising at least one solvent and perovskite precursors so as to form a wet film on the deposition face, the depositing being carried out by slot die coating or via a blade coating, the precursors comprising at least CsX, FAY, PbZ 2 , with X, Y and Z═I, Br, and an FACl additive, the amounts being determined such that the molar ratio of cesium to lead is comprised between about 4% and 22%, preferably between 13% and 20%, that the molar ratio of FACl relative to lead is comprised between 0.1% and 5%, in particular between 0.1% and 2%, and that the perovskite layer has a empirical formula of the Cs x FA (1−x+w) Pb(I y Br (1−y) ) 3 type with x comprised between 0.04 and 0.22, y comprised between 0 and 1 and w comprised between 0.001 and 0.05, and c) sweeping an exposed surface of the wet film by a flow of dry air or inert gas having a speed greater than or equal to 120 m/s so as to crystallize the multi-cations perovskite layer, the method further comprising the application of a heat treatment to the substrate so that the deposition face has a temperature ranging from about 25° C. to 80° C. at least during step b).
2 . The manufacturing method according to claim 1 , wherein step c) of sweeping with a flow of inert gas or dry air is carried out by a relative displacement of the substrate comprising the wet film and a projection nozzle, such as a projection nozzle of a gas knife, the projection nozzle being arranged such that the length of the flow path of the inert gas or dry air between the outlet of the projection nozzle and the exposed surface of the wet film is comprised between about 3.1 millimeters and 6 millimeters.
3 . The manufacturing method according to claim 2 , wherein the speed of relative movement between the wet film and the projection nozzle (6) during step c) is comprised between 1 and 50 mm/s.
4 . The manufacturing method according to claim 2 , wherein the angle α formed between the flow of inert gas or dry air and the wet film is comprised between 90° and 45°.
5 . The manufacturing method according to claim 1 , wherein the application of a heat treatment to the substrate is carried out so that the deposition face has a temperature ranging between about 30° C. and 70° C.
6 . The manufacturing method according to claim 1 , wherein the precursors of the perovskite layer are selected from a combination of CsX, FAY and PbZ 2 , with X, Y and Z═I, Br and the FACl additive.
7 . The manufacturing method according to claim 1 , wherein the at least one solvent is selected from DMF and/or DMSO.
8 . The manufacturing method according to claim 1 , wherein the molar concentration of lead in the precursor solution is comprised between 0.5 M and 1.7 M.
9 . The manufacturing method according to claim 1 , wherein the only thermal budget applied during the manufacturing method is provided by the heat treatment applied to the substrate so that the deposition face has a temperature ranging from about 25° C. to 80° C. during steps b) and c).
10 . The manufacturing method according to claim 1 , wherein step c) of applying the flow of inert gas or dry air is followed by a step d) of applying a thermal annealing carried out at a temperature comprised between 70° C. and 100° C.
11 . The manufacturing method according to claim 1 , wherein step b) of depositing the precursor solution is carried out so as to obtain a constant wet film thickness comprised between 2 and 16 micrometers.

Description

The present invention relates to the field of layers of material of the perovskite type for applications in the microelectronics and optoelectronics field. More particularly, the present invention concerns a method for manufacturing a photo-active halogenated hybrid perovskite layer, and in particular a multi-cation perovskite layer, for a use in photovoltaic devices, LEDs, photo-detectors, micro-batteries, or other devices using their semi-conductive properties. The halogenated hybrid perovskites are promising materials and many developments are being implemented to improve their quality and stability, in particular for the manufacture of solar cells. Indeed, hybrid organic-inorganic lead halide perovskite solar cells showed a remarkable increase in energy conversion efficiency over a relatively short period of time (10 years). Nonetheless, the challenges of this technology are 1) the scaling up of the deposition methods of the different layers, especially the perovskite layer, 2) the stability of the photovoltaic devices under real conditions and 3) the presence of Pb in the absorbent layer of these devices. This invention relates to the first point. Indeed, most of the manufacturing methods that have been developed to date to deposit a perovskite material having physical and optoelectronic properties leading to high photovoltaic performances (>20%) are carried out on a laboratory scale, on small areas. Thus, there remains a need for the design and optimization of methods allowing the manufacture of quality perovskite layers, on an industrial scale, at a reasonable cost and without degradation of their properties. When a spin coating method is used, the precursors of the target perovskite layer are placed in solution to be spread on a rotating substrate. The projection of an anti-solvent on the rotating substrate makes it possible to initiate the nucleation of the perovskite and thus to obtain covering films of high optoelectronic quality. Nonetheless, when this deposition method is used over a large surface, a non-homogeneous wet film is produced, due to the inhomogeneity of the centrifugal effect. Other deposition methods exist such as blade coating, slot die coating, or inkjet printing, etc., Although these methods are more suitable for depositing a precursor solution on an industrial scale, a major problem lies in the difficulty of obtaining the crystallization of the perovskite film spread on the substrate, whatever the method of formation of the film. The use of the anti-solvent method, based on the centrifugal effect, is not very suitable for large substrates. In addition, this method typically uses a toxic or dangerous solvent (chlorobenzene or toluene) with operators working in glove boxes, an environment not suitable for use on an industrial scale. Finally, during the implementation under air, desirable for an application on an industrial scale, the obtained devices can present limited performances, in particular in term of Voc. One of the aims of the present invention is to overcome at least one of these drawbacks. To this end, the invention proposes a method for manufacturing a multi-cation perovskite layer, with a view to form a photo-active layer, the method comprising the steps of: a) suppling a substrate having a deposition face,b) depositing a precursor solution comprising at least one solvent and perovskite precursors so as to form a wet film on the deposition face, the precursors comprising at least CsX, FAY, PbZ2, with X, Y and Z═I, Br, and an additive of FACl, the amounts being determined such that the molar ratio of cesium relative to lead is comprised between about 4% and 22%, preferably between 13% and 20%, that the molar ratio of FACl relative to lead is comprised between 0.1% and 5%, in particular between 0.1% and 2%, and that the perovskite layer has a molecular formula of the type CSxFA(1−x+w)Pb (IyBr(1−y))3 with x comprised between 0.04 and 0.22, y comprised between 0 and 1, and w comprised between 0.001 and 0.05, andc) sweeping an exposed surface of the wet film by a flow of dry air or inert gas having a speed greater than or equal to 120 m/s so as to crystallize the multi-cation perovskite layer,the method further comprising the application of a heat treatment to the substrate so that the deposition face has a temperature ranging from about 25° C. to at least 80° C. during step b). Against all expectation, this combination of parameters relating to the heat treatment applied to the substrate, the composition of the used precursor solution, the presence of a chlorinated additive, the deposition method and the crystallization method, in particular the speed of the gas flow associated with the composition of the precursor solution makes it possible to obtain a perovskite layer of very good crystalline quality, over its entire surface, as can be seen below. In addition, the manufacture of photovoltaic cells using the photo-active perovskite layer thus manufactured gives efficien