Methods for producing light-absorbing materials with perovskite structure and liquid polyhalides of variable composition for their implementation

Abstract

Organic-inorganic light-absorbing materials with perovskite structure, being used in perovskite solar cells production. The objective of the invention is to provide the possibility of obtaining perovskite using precursors that are in a liquid state without the use of additional substances and reagents. The concept of the invention is based on the fact that a light-absorbing material with perovskite structure with general formula ADB.sub.3, where A stands for methylammonium MA.sup.+ (CH.sub.3NH.sub.3.sup.+), formamidinium, FA.sup.+ ((NH.sub.2).sub.2CH.sup.+), guanidinium Gua (C(NH2)3+), cesium Cs.sup.+ or a mixture thereof, B stands for Cl.sup.−, Br.sup.−, I.sup.− or a mixture thereof, while the component D represents Sn, Pb, Bi or a mixture thereof, is obtained by mixing composition AB-nB.sub.2 and a component containing D, where the component containing D is chosen from elemental Sn, Pb, Bi and/or their salts, mixtures, alloys, whereas the composition AB-nB.sub.2 is deposited onto the component D followed by subsequent removal of the excessive components, n is greater than or equal to one, the component B.sub.2 represents Cl.sub.2, Br.sub.2, I.sub.2 or a mixture thereof.

Claims

1. A method for producing a light absorbing material with perovskite structure and chemical formula ADB.sub.3, the method comprising: mixing a composition that comprises AB-nB.sub.2 with a reagent that comprises component D to yield ADB.sub.3 and removing excess component D, wherein: A is selected from the group of cations consisting of: CH.sub.3NH.sub.3.sup.+, (NH.sub.2).sub.2CH.sup.+, C(NH.sub.2).sub.3.sup.+, Cs.sup.+ and mixtures of thereof, B is selected from the group of anions consisting of: Cl.sup.−, Br.sup.−, I.sup.− and mixtures of thereof, B.sub.2 is an elemental halogen selected from the group consisting of: Cl.sub.2, Br.sub.2, and I.sub.2, or a mixture thereof, and D is selected from the group of elements consisting of: elemental Sn, Pb, Bi and mixture, alloys and salts thereof.

2. The method according to claim 1, wherein the mixing of the composition AB-nB.sub.2 with the reagent that comprises component D is performed by dissolving the reagent that comprises component D in the composition that comprises AB-nB.sub.2 with a consequent thermal treatment.

3. The method according to claim 1, wherein the mixing of the composition AB-nB.sub.2 with the reagent that comprises component D is performed by dissolving the reagent that comprises component D in the composition that comprises AB-nB.sub.2 with a consequent pressure decrease.

4. The method according to claim 1, wherein the mixing of the composition AB-nB.sub.2 with the reagent that comprises component D is performed by dissolving the reagent that comprises component D in a mixture that contains components A, B and D with a consequent thermal treatment.

5. The method according to claim 1, wherein the mixing of the composition AB-nB.sub.2 with the reagent that comprises component D is performed by dissolving D in a mixture that contains components A, B and D with a consequent pressure decrease.

6. The method according to claim 1, wherein the mixing of the composition AB-nB.sub.2 with the reagent that comprises component D is performed by depositing AB-nB.sub.2 on the reagent that comprises component D.

7. The method according to claim 6, wherein the deposition of AB-nB.sub.2 on the reagent that comprises component D is performed by any of the following or a combination thereof: spin-coating, spray-coating, immersion, blade coating, drop-casting, roll-to-roll deposition or screen printing.

8. The method according to claim 1, wherein an excess of component B from the composition AB-nB.sub.2 is removed by any of the following methods or a combination thereof: washing with a solvent, thermal treatment of the substrate, removal under the reduced pressure or removal using sorbent.

Description

EXAMPLE 1

(1) A reagent MAI-2I.sub.2 is obtained by mixing 159 mg MAI and 508 mg I.sub.2 which is then spin-coated on top of the substrate of the following configuration: FTO/TiO.sub.2/Pb with a metallic lead layer 250 nm thick (FTO stands for fluorine-doped tin oxide). The substrate is then heated and kept at a temperature of 115° C. for 30 minutes. As a result, a perovskite layer MAPbI.sub.3 is formed on the substrate.

EXAMPLE 2

(2) A powder of metallic lead (20 mg) is added to the reagent AB-nB.sub.2 (A=MA; B=I, Br; n≥1) that is obtained by mixing 127 mg MAI, 22 mg MABr, and 508 mg I.sub.2 and this mixture is stirred for 12 hours. The mixture is then filtered using the syringe filter (PTFE, 0.45 μm pore-diameter) and spin-coated on top of metallic lead 50 nm-thick on glass substrate. After the spin-coating process, the substrate is immersed into the isopropanol bath, removed and dried. As a result, a perovskite layer MAPbI.sub.xBr.sub.3−x is formed on the glass substrate.

EXAMPLE 3

(3) A reagent AB-nB.sub.2 (A=MA, FA; B=I, Br; n≥1) is obtained by mixing FAI (137 mg), MABr (22 mg) and I.sub.2 (508 mg) which is then spin-coated on top of metallic lead 250 nm-thick on glass substrate. Just 15 seconds before the rotation of the sample-holder ends, 100 μl of the isopropyl alcohol is dropped onto the surface of the sample. As a result, a perovskite layer MA.sub.xFA.sub.1−xPbI.sub.3yBr.sub.3−3y (0≤x≤1; 0≤y≤1) is formed on the glass substrate.

(4) See below the ways of preparation of liquid polyhalides composition with a general formula AB-nB.sub.2.

EXAMPLE 4

(5) 1016 mg (4 mmol) of crystalline iodine in the form of a solid powder is added at room temperature to 318 mg (2 mmol) of crystalline MAI in the form of a solid powder. After that, the mixture is stirred for 3 minutes at room temperature, resulting in the formation of a dark brown liquid with a composition MAI-2I.sub.2. After preparation, the composition retains its properties for at least a month at room temperature.

EXAMPLE 5

(6) 1270 mg (5 mmol) of crystalline iodine in the form of a solid powder is added at room temperature to 318 mg (2 mmol) of crystalline MAI in the form of a solid powder. After that, the mixture is stirred for 3 minutes at 40° C. and cooled down to room temperature, resulting in the formation of a dark brown liquid with a composition MAI-2.5I.sub.2. After preparation, the composition retains its properties for at least a month at room temperature.

EXAMPLE 6

(7) 2540 mg (10 mmol) of crystalline iodine in the form of a solid powder is heated in a closed vial up to 120° C. which causes iodine melting. Then, 318 mg (2 mmol) of crystalline MAI in the form of a solid powder is added in the vial. After that, the mixture is stirred for 3 minutes and cooled down to 70° C., resulting in the formation of dark brown liquid with a composition MAI-5I.sub.2. After preparation, the composition retains its properties for at least a month at 70° C.