A method for preparing photoactive perovskite materials. The method comprises the steps of preparing a bismuth halide precursor ink. Preparing a bismuth halide precursor ink comprises the steps of introducing a bismuth halide into a vessel; introducing a first solvent to the vessel; and contacting the bismuth halide with the first solvent to dissolve the bismuth halide to form the bismuth halide precursor ink; depositing the bismuth halide precursor ink onto a substrate; drying the bismuth halide precursor ink to form a thin film; annealing the thin film; and rinsing the thin film with a solvent comprising: a second solvent; a first salt selected from the group consisting of methylammonium halide, formamidinimum halide, guanidinium halide, 1,2,2-triaminovinylammonium halide, and 5-aminovaleric acid hydrohalide; and a second salt selected from the group consisting of methylammonium halide, formamidinimum halide, guanidinium halide, 1,2,2-triaminovinylammonium halide, and 5-aminovaleric acid hydrohalide.

The invention provides an optoelectronic device comprising a porous material, which porous material comprises a semiconductor comprising a perovskite. The porous material may comprise a porous perovskite. Thus, the porous material may be a perovskite material which is itself porous. Additionally or alternatively, the porous material may comprise a porous dielectric scaffold material, such as alumina, and a coating disposed on a surface thereof, which coating comprises the semiconductor comprising the perovskite. Thus, in some embodiments the porosity arises from the dielectric scaffold rather than from the perovskite itself. The porous material is usually infiltrated by a charge transporting material such as a hole conductor, a liquid electrolyte, or an electron conductor. The invention further provides the use of the porous material as a semiconductor in an optoelectronic device. Further provided is the use of the porous material as a photosensitizing, semiconducting material in an optoelectronic device. The invention additionally provides the use of a layer comprising the porous material as a photoactive layer in an optoelectronic device. Further provided is a photoactive layer for an optoelectronic device, which photoactive layer comprises the porous material.

The invention provides an optoelectronic device comprising a porous material, which porous material comprises a semiconductor comprising a perovskite. The porous material may comprise a porous perovskite. Thus, the porous material may be a perovskite material which is itself porous. Additionally or alternatively, the porous material may comprise a porous dielectric scaffold material, such as alumina, and a coating disposed on a surface thereof, which coating comprises the semiconductor comprising the perovskite. Thus, in some embodiments the porosity arises from the dielectric scaffold rather than from the perovskite itself. The porous material is usually infiltrated by a charge transporting material such as a hole conductor, a liquid electrolyte, or an electron conductor. The invention further provides the use of the porous material as a semiconductor in an optoelectronic device. Further provided is the use of the porous material as a photosensitizing, semiconducting material in an optoelectronic device. The invention additionally provides the use of a layer comprising the porous material as a photoactive layer in an optoelectronic device. Further provided is a photoactive layer for an optoelectronic device, which photoactive layer comprises the porous material.

The embodiment provides a graphene-containing membrane producible by wet-coating and excellent in electric properties, a process for producing the membrane, a graphene-containing membrane laminate, and a photoelectric conversion device using the graphene-containing membrane. The graphene-containing membrane contains graphene having a graphene skeleton combined with polyalkylenimine chains. The membrane has a ratio of the photoelectron intensity at the energy peak position of C1s orbital to that at the bonding energy on an X-ray photoelectron spectrum measured on an ITO film of 288 eV in a range of 5.5 to 20. This membrane can be produced by heating a graphene oxide-containing film in the presence of polyalkyleneimine and further heating the film in the presence of a reducing agent. The graphene-containing membrane can be so installed in a photoelectric conversion device that it is placed between the photoelectric conversion layer and the electrode.

A photodetector having a small form factor and having high detection efficiency with respect to both visible light and infrared rays may include a first electrode, a collector layer on the first electrode, a tunnel barrier layer on the collector layer, a graphene layer on the tunnel barrier layer, an emitter layer on the graphene layer, and a second electrode on the emitter layer. The photodetector may be included in an image sensor. An image sensor may include a substrate, an insulating layer on the substrate, and a plurality of photodetectors on the insulating layer. The photodetectors may be aligned with each other in a direction extending parallel or perpendicular to a top surface of the insulating layer. The photodetector may be included in a LiDAR system.

Provided is a quantum dot light-emitting device and a display apparatus including the same. The quantum dot light-emitting device comprises: an anode; a cathode; a hole transport layer disposed between the anode and the cathode; a light-emitting layer disposed between the hole transport layer and the cathode, the light-emitting layer including a quantum dot having a core-shell structure; and a buffer layer disposed between the hole transport layer and the light-emitting layer, wherein the buffer layer contains an organic compound or derivatives thereof. The external quantum efficiency and device stability are improved. an aromatic hydrocarbon compound or derivatives thereof having a functional group selected from the group consisting of a hydroxyl group (—OH), a carboxyl group (—COOH), an amino group (—NR, —NH, —NH.sub.2, where R is a C1 to C6 monovalent hydrocarbon group or derivatives thereof) and a thiol group (—SH).

A positive-intrinsic-negative (PIN) photosensitive device is provided. A p-type semiconductor layer composed of molybdenum oxide and having valence band energy between valence band energy of an intrinsic semiconductor layer and an upper electrode is used to replace a p-type semiconductor layer used in a conventional PIN photodiode, so that the PIN photodiode may be prepared without using borane gas. More, a difference between valence band energy of the p-type semiconductor layer and the intrinsic semiconductor layer is used to transport holes located in a valence band, so that it is unnecessary to use an active layer of a thin film transistor, so that the PIN photosensitive device may be stacked on the thin film transistor to reduce aperture ratio loss of a display panel.

The embodiment provides a graphene-containing membrane producible by wet-coating and excellent in electric properties, a process for producing the membrane, a graphene-containing membrane laminate, and a photoelectric conversion device using the graphene-containing membrane. The graphene-containing membrane contains graphene having a graphene skeleton combined with polyalkyleneimine chains. The membrane has a ratio of the photoelectron intensity at the energy peak position of C1s orbital to that at the bonding energy on an X-ray photoelectron spectrum measured on an ITO film of 288 eV in a range of 5.5 to 20. This membrane can be produced by heating a graphene oxide-containing film in the presence of polyalkyleneimine and further heating the film in the presence of a reducing agent. The graphene-containing membrane can be so installed in a photoelectric conversion device that it is placed between the photoelectric conversion layer and the electrode.

The invention provides an optoelectronic device comprising: (i) a porous dielectric scaffold material; and (ii) a semiconductor having a band gap of less than or equal to 3.0 eV, in contact with the scaffold material. Typically the semiconductor, which may be a perovskite, is disposed on the surface of the porous dielectric scaffold material, so that it is supported on the surfaces of pores within the scaffold. In one embodiment, the optoelectronic device is an optoelectronic device which comprises a photoactive layer, wherein the photo-active layer comprises: (a) said porous dielectric scaffold material; (b) said semiconductor; and (c) a charge transporting material. The invention further provides the use, as a photoactive material in an optoelectronic device, of: (i) a porous dielectric scaffold material; and (ii) a semi-conductor having a band gap of less than or equal to 3.0 eV, in contact with the scaffold material. Further provided is the use of a layer comprising: (i) a porous dielectric scaffold material; and (ii) a semiconductor having a band gap of less than or equal to 3.0 eV, in contact with the scaffold material; as a photoactive layer in an optoelectronic device. In another aspect, the invention provides a photoactive layer for an optoelectronic device comprising (a) a porous dielectric scaffold material; (b) a semiconductor having a band gap of less than or equal to 3.0 eV, in contact with the scaffold material; and (c) a charge transporting material.

The invention provides an optoelectronic device comprising a porous material, which porous material comprises a semiconductor comprising a perovskite. The porous material may comprise a porous perovskite. Thus, the porous material may be a perovskite material which is itself porous. Additionally or alternatively, the porous material may comprise a porous dielectric scaffold material, such as alumina, and a coating disposed on a surface thereof, which coating comprises the semiconductor comprising the perovskite. Thus, in some embodiments the porosity arises from the dielectric scaffold rather than from the perovskite itself. The porous material is usually infiltrated by a charge transporting material such as a hole conductor, a liquid electrolyte, or an electron conductor. The invention further provides the use of the porous material as a semiconductor in an optoelectronic device. Further provided is the use of the porous material as a photosensitizing, semiconducting material in an optoelectronic device. The invention additionally provides the use of a layer comprising the porous material as a photoactive layer in an optoelectronic device. Further provided is a photoactive layer for an optoelectronic device, which photoactive layer comprises the porous material.