The present invention provides a method of forming a crystalline or polycrystalline layer of an organic-inorganic metal halide perovskite material comprising a three-dimensional crystal structure represented by the formula AMX .sub.3, in which A represents an organic cation or a mixture of two or more different cations, at least one of which is an organic cation, M represents a divalent metal cation or a mixture of two or more different divalent metal cations, and X represents halide anions which are the same or different, the method comprising the steps of: (i) forming a first layer on the surface of a substrate, the first layer comprising an organic-inorganic metal halide perovskite material having a planar, layered two-dimensional crystal structure (ii) reacting the first layer with one or more organic halides to form the crystalline or polycrystalline layer comprising an organic-inorganic metal halide perovskite material having the formula AMX .sub.3. Also provided is an optoelectronic or photovoltaic device including an active layer comprising an organic-inorganic metal halide perovskite material comprising a three-dimensional crystal structure represented by the formula AMX .sub.3, wherein the material is obtainable using the above defined method.

The present invention provides a method of forming a crystalline or polycrystalline layer of an organic-inorganic metal halide perovskite material comprising a three-dimensional crystal structure represented by the formula AMX .sub.3, in which A represents an organic cation or a mixture of two or more different cations, at least one of which is an organic cation, M represents a divalent metal cation or a mixture of two or more different divalent metal cations, and X represents halide anions which are the same or different, the method comprising the steps of: (i) forming a first layer on the surface of a substrate, the first layer comprising an organic-inorganic metal halide perovskite material having a planar, layered two-dimensional crystal structure (ii) reacting the first layer with one or more organic halides to form the crystalline or polycrystalline layer comprising an organic-inorganic metal halide perovskite material having the formula AMX .sub.3. Also provided is an optoelectronic or photovoltaic device including an active layer comprising an organic-inorganic metal halide perovskite material comprising a three-dimensional crystal structure represented by the formula AMX .sub.3, wherein the material is obtainable using the above defined method.

Aspects concern an organic metal-halide perovskite precursor including a divalent metal cation, a halide anion, and an alkylamine, wherein the divalent metal cation is connected to a nitrogen atom of the alkylamine via a covalent bond. Further aspects concern a process for the production of the organic metal-halide perovskite precursor and a perovskite ink including the organic metal-halide perovskite precursor and a non-coordinating solvent.

Aspects concern an organic metal-halide perovskite precursor including a divalent metal cation, a halide anion, and an alkylamine, wherein the divalent metal cation is connected to a nitrogen atom of the alkylamine via a covalent bond. Further aspects concern a process for the production of the organic metal-halide perovskite precursor and a perovskite ink including the organic metal-halide perovskite precursor and a non-coordinating solvent.

Provided is an adduct represented by Formula 1:
A.PbY.sub.2.Q  (1) wherein A is an organic or inorganic halide, Y is F.sup.−, Cl.sup.−, Br.sup.− or I.sup.− as a halogen ion, and Q is a Lewis base including a functional group containing a nitrogen (N), oxygen (O) or sulfur (S) atom with an unshared pair of electrons as an electron pair donor. The Lewis base is maintained more stable in the lead halide adduct. Therefore, the use of the adduct enables the fabrication of a perovskite solar cell with high conversion efficiency.

Provided is an adduct represented by Formula 1:
A.PbY.sub.2.Q  (1) wherein A is an organic or inorganic halide, Y is F.sup.−, Cl.sup.−, Br.sup.− or I.sup.− as a halogen ion, and Q is a Lewis base including a functional group containing a nitrogen (N), oxygen (O) or sulfur (S) atom with an unshared pair of electrons as an electron pair donor. The Lewis base is maintained more stable in the lead halide adduct. Therefore, the use of the adduct enables the fabrication of a perovskite solar cell with high conversion efficiency.

The present invention relates to specific complexes comprising heavy metal ions having an atomic number of 29 or higher and 83 or lower (preferably 29 or higher and 81 or lower) and one or more ligand(s) selected from the group consisting of specific xanthene derivatives, preferably eosin Y and/or erythrosin B ligand(s). In particular, the invention relates to the use of the complexes as ex vivo contrast agents for a computed tomography scanning of a biological sample. Moreover, the invention relates to specific ex vivo methods for investigating a biological sample by means of computed tomography scanning methods, wherein the method comprises staining the biological sample with a solution comprising one or more of the complex(es); or wherein the method comprises staining the biological sample with a staining solution comprising one or more specific xanthenes derivatives (e.g. eosin Y and/or erythrosin B), and separately contacting the biological sample with one or more staining solution(s) comprising one or more heavy metal ions having an atomic number of 29 or higher and 83 or lower (preferably 29 or higher and 81 or lower).

Provided are metal halide perovskite light emitting device and method of manufacturing the same. The metal halide perovskite light emitting device uses perovskite film having a multi-dimensional crystal structure derived from a proton transfer reaction as light emitting layer. Due to self-assembled shell of the perovskite film, ion movement is suppressed and surface defects are removed. Thereby, photoluminescence intensity, luminescence efficiency and lifetime are improved. By injecting a fluorine-based material and a basic material into the PEDOT:PSS conductive polymer used as the conventional hole injection layer, the acidity is controlled and the work function of the interface is improved. Furthermore, chemically stable graphene barrier layer protects the electrode vulnerable to acid, so that a high-efficiency light emitting device can be manufactured.

Provided are metal halide perovskite light emitting device and method of manufacturing the same. The metal halide perovskite light emitting device uses perovskite film having a multi-dimensional crystal structure derived from a proton transfer reaction as light emitting layer. Due to self-assembled shell of the perovskite film, ion movement is suppressed and surface defects are removed. Thereby, photoluminescence intensity, luminescence efficiency and lifetime are improved. By injecting a fluorine-based material and a basic material into the PEDOT:PSS conductive polymer used as the conventional hole injection layer, the acidity is controlled and the work function of the interface is improved. Furthermore, chemically stable graphene barrier layer protects the electrode vulnerable to acid, so that a high-efficiency light emitting device can be manufactured.

A method for obtaining a salt with a general formula: R.sub.xNI, wherein: R.sub.xN is an organic cation (R.sub.xN.sup.+), R represents substituents (R−) independently selected from a group consisting of organic substituents: R.sup.1−, R.sup.2—, R.sup.3— and hydrogen (H—), x is a number of the substituents R— directly linked with the nitrogen (N) atom in the organic cation R.sub.xN.sup.+, wherein x is 3 or 4, I is an iodide anion (I.sup.−). The method comprises: preparing a reaction mixture comprising the steps of: synthesizing hydrogen iodide (HI) in situ by mixing molecular iodine (I.sub.2) with formic acid (COOH) in a molar ratio of molecular iodine (I.sub.2): formic acid (COOH) of no less than 1.01:1, in a solvent medium, introducing into the solvent medium a compound being a donor of organic cation R.sub.xN.sup.+ in an amount providing the molar ratio of the donor of organic cation R.sub.xN.sup.+: molecular iodine (I.sub.2) of no less than 1.01:1, and maintaining the reaction mixture at a temperature of not less than 20° C. for the time necessary to obtain the reaction product being the salt with the general formula R.sub.xNI. The obtained product is a substrate for synthesis of perovskites.