The present invention aims to provide a solar cell having high durability against deterioration due to moisture ingress from the side surfaces. The solar cell 10 of the present invention includes: first and second electrodes 12 and 17; a perovskite layer 14 provided between the first and second electrodes 12 and 17 and containing an organic-inorganic perovskite compound (A) represented by the formula RMX.sub.3 where R is an organic molecule, M is a metal atom, and X is a halogen atom; and a side-surface-protecting layer 15 provided on a peripheral side of the perovskite layer 14 to coat at least part of a side surface of the perovskite layer 14, the side-surface-protecting layer 15 containing at least one selected from the group consisting of a metal halide (B1) and an organometal halide (B2) or containing an organohalide (C).

The present invention aims to provide a solar cell having high durability against deterioration due to moisture ingress from the side surfaces. The solar cell 10 of the present invention includes: first and second electrodes 12 and 17; a perovskite layer 14 provided between the first and second electrodes 12 and 17 and containing an organic-inorganic perovskite compound (A) represented by the formula RMX.sub.3 where R is an organic molecule, M is a metal atom, and X is a halogen atom; and a side-surface-protecting layer 15 provided on a peripheral side of the perovskite layer 14 to coat at least part of a side surface of the perovskite layer 14, the side-surface-protecting layer 15 containing at least one selected from the group consisting of a metal halide (B1) and an organometal halide (B2) or containing an organohalide (C).

A photoelectric conversion film according to the present disclosure includes a perovskite compound including a monovalent formamidinium cation, a Pb cation and an iodide ion, and a substance having Hansen solubility parameters satisfying a dispersion term δ.sub.D of 20±0.5 MPa.sup.0.5, a polar term δ.sub.P of 18±1 MPa.sup.0.5 and a hydrogen bonding term δ.sub.H of 11±2 MPa.sup.0.5.

The present disclosure relates to novel perovskite solar cells, and the method of making and using the novel perovskite solar cells. More specifically, a triple cation perovskite solar cell device containing a multifunctional capping layer (MCL) of R.sup.1NH.sub.3.sup.+ and/or a thin layer of two-dimensional (2D) material of (R.sup.1NH.sub.3.sup.+).sub.2(A.sup.+).sub.n−1(M.sup.2+).sub.n(X.sup.−).sub.3n+1 on top of the commonly used ABX3 perovskite, with enhanced power conversion efficiency of 22.06% (from 19.94%) with long-term stability over 1000 hours under continuous illumination has been developed.

A halide material having general formula ArMAX is disclosed. The halide material can be processed to an optoelectronic film with a halogenated formamidine and a lead halide, and the optoelectronic film can be applied in the manufacture of an optoelectronic device like a perovskite laser or a PeLED. Experimental data have proved that, the fabricated optoelectronic film shows a property of photoluminescence (PL) peak wavelength adjustable. Moreover, the PL peak wavelength moves from 482 nm to 534 nm with the increase of the content of lead (Pb), halogen (X) and formamidine (FA) in the optoelectronic film Furthermore, experimental data have also indicated that, the fabricated optoelectronic film can be used as a blue emissive layer, a red emissive layer or a green emissive layer, thereby having a significant potential for application in optoelectronics industry.

A halide material having general formula ArMAX is disclosed. The halide material can be processed to an optoelectronic film with a halogenated formamidine and a lead halide, and the optoelectronic film can be applied in the manufacture of an optoelectronic device like a perovskite laser or a PeLED. Experimental data have proved that, the fabricated optoelectronic film shows a property of photoluminescence (PL) peak wavelength adjustable. Moreover, the PL peak wavelength moves from 482 nm to 534 nm with the increase of the content of lead (Pb), halogen (X) and formamidine (FA) in the optoelectronic film Furthermore, experimental data have also indicated that, the fabricated optoelectronic film can be used as a blue emissive layer, a red emissive layer or a green emissive layer, thereby having a significant potential for application in optoelectronics industry.

The invention relates to a process for chemically etching the surface of a metal halide perovskite, the process comprising treating the metal halide perovskite with one or more multidentate ligands, wherein the one or more multidentate ligands comprise an organic compound or a salt thereof, which organic compound comprises three or more binding groups. A chemically etched metal halide perovskite, a process for producing a semiconductor device, a composition and a semiconductor device are also described.

The invention relates to a process for chemically etching the surface of a metal halide perovskite, the process comprising treating the metal halide perovskite with one or more multidentate ligands, wherein the one or more multidentate ligands comprise an organic compound or a salt thereof, which organic compound comprises three or more binding groups. A chemically etched metal halide perovskite, a process for producing a semiconductor device, a composition and a semiconductor device are also described.

A method for fabricating a perovskite film includes the steps of: placing a substrate on a substrate stage in a chamber, the substrate stage configured to rotate around its central axis at a rotation speed; depositing first source materials on the substrate from a first set of evaporation units, each coupled to the side section or the bottom section of the chamber; depositing second source materials on the substrate from a second set of evaporation units coupled to the bottom section, wherein the chamber includes a shield defining two or more zones having respective horizontal cross-sectional areas, which are open and facing the substrate, designated for the two or more evaporation units in the second set. The perovskite film includes multiple unit layers each being formed by one rotation of the substrate stage, and having composition and thickness thereof controlled by adjusting evaporation rates, rotation speed and horizontal cross-sectional areas.

The invention relates to an optoelectronic device comprising: (a) a layer comprising a crystalline A/M/X material, wherein the crystalline A/M/X material comprises a compound of formula: [A]a [M]b [X]c wherein: [A] comprises one or more A cations; [M] comprises one or more M cations which are metal or metalloid cations; [X] comprises one or more X anions; a is a number from 1 to 6; b is a number from 1 to 6; and c is a number from 1 to 18; and (b) an ionic liquid which is a salt comprising an organic cation and a counter anion, wherein the organic cation is present within the layer comprising the crystalline A/M/X material. The invention also relates to processes for producing an ionic liquid-modified film of a crystalline A/M/X material and a process for producing an optoelectronic device comprising an ionic-liquid modified film of a crystalline A/M/X material.