Methods are described that include contacting an alkyl ammonium metal halide film with an alkyl ammonium halide, where the alkyl ammonium metal halide film includes a first halogen and a metal, the alkyl ammonium halide includes a second halogen, such that the contacting forms an alkyl ammonium metal mixed-halide film that interfaces with the alkyl ammonium metal halide film, where the alkyl ammonium metal mixed-halide film includes the first halogen, the second halogen, and the metal.

A foldable display device including a lower module having a first side end disposed in a first side area of the foldable display device; a display module including: a main region including a display area and a first side end disposed in the first side area; a sub region disposed under the lower module, overlapping the main region, and having a first side end disposed in the first side area; and a bent region disposed between the first side ends of the main region and the sub region and having an outer surface between an upper surface of the main region and a lower surface of the sub region, and an inner surface between a lower surface of the main region and an upper surface of the sub region; and a functional module and a window module each having a first side end disposed in the first side area.

The disclosure provides a precursor solution, a perovskite solar cell and a preparation method thereof. The solute of the precursor solution includes a metal halide, the solvent of the precursor solution is an organic solvent, and the precursor solution contains nanobubbles, which have a diameter not more than 1000 nm, and the zeta potential of the precursor solution does not exceed −20 mV. The method of preparing the precursor solution includes: (1) preparing an organic solvent containing nanobubbles; (2) dissolving a solute in the organic solvent containing nanobubbles. The precursor solution of the disclosure has a very low zeta potential, and the nanobubbles can exist stably in the organic solvent(s) for up to one month. When comparing with traditional methods for preparing the precursor solution of the perovskite cells, the method for preparing the precursor solution of the disclosure can effectively improve the stability, reproducibility and solubility of the metal halide in the organic solvent(s).

Perovskite single crystal X-ray radiation detector devices including an X-ray wavelength-responsive active layer including an organolead trihalide perovskite single crystal, a substrate layer comprising an oxide, and a binding layer disposed between the active layer and the substrate layer. The binding layer including a binding molecule having a first functional group that bonds to the organolead trihalide perovskite single crystal and a second functional group that bonds with the oxide. Inclusion of the binding layer advantageously reduces device noise while retaining signal intensity.

A solid junction-type photoelectric conversion element (10) including a first conductive layer (2), an electric power generation layer (4), and a second conductive layer (6), which are laminated in this order, wherein the electric power generation layer (4) comprises: a perovskite compound represented by a composition formula ABX.sub.3, formed of an organic cation A, a metal cation B and a halide anion X, and a compound Z having no perovskite structure.

Provided are devices and methods to detect the presence of volatile organic compounds related to the presence of a disease state in a biological sample. The devices may include a detection moiety such as a polynucleoide in electronic communication with a semiconductor such as graphene or a carbon nanotube.

A composite material, quantum dot light-emitting diode and preparation method thereof. The preparation method includes: providing ZnO nanoparticles and Au source, Au source is at least one of bulk Au or Au particles; mixing ZnO nanoparticles, Au source, S source with first organic solvent, performing hydrothermal reaction to prepare composite material. By performing hydrothermal reaction in organic solvent using ZnO nanoparticles, bulk Au and/or Au particles, and S source, S source can vulcanize surface of ZnO nanoparticles to form ZnS layer on surface of ZnO nanoparticles, Au source can be thermally dissolved and diffused into isolated distribution of atomic-level Au to realize loading on surface of ZnS layer, to obtain composite material with ZnO nanoparticles as core material, ZnS and Au as shell material. ZnS and Au in composite material can synergistically increase electron transmission efficiency of LED adopting same.

The invention provides an optoelectronic device comprising a photoactive region, which photoactive region comprises: an n-type region comprising at least one n-type layer; a p-type region comprising at least one p-type layer; and, disposed between the n-type region and the p-type region: a layer of a perovskite semiconductor without open porosity. The perovskite semiconductor is generally light-absorbing. In some embodiments, disposed between the n-type region and the p-type region is: (i) a first layer which comprises a scaffold material, which is typically porous, and a perovskite semiconductor, which is typically disposed in pores of the scaffold material; and (ii) a capping layer disposed on said first layer, which capping layer is said layer of a perovskite semiconductor without open porosity, wherein the perovskite semiconductor in the capping layer is in contact with the perovskite semiconductor in the first layer. The layer of the perovskite semiconductor without open porosity (which may be said capping layer) typically forms a planar heterojunction with the n-type region or the p-type region. The invention also provides processes for producing such optoelectronic devices which typically involve solution deposition or vapour deposition of the perovskite. In one embodiment, the process is a low temperature process; for instance, the entire process may be performed at a temperature or temperatures not exceeding 150° C.

The present application provides a preparation method of a charge transport layer, which includes steps of: forming a first film layer by a first solution containing a functional material, forming a second film layer by a second solution containing a charge transport material, the first film layer and the second film layer are in contact with each other, or forming a mixed film layer by a mixed solution of the first solution and the second solution; and removing the functional material to obtain a charge transport layer. The functional material is an organic substance containing an electron-donating group, a surface of the charge transport material has a metal cation dangling bond, and the electron-donating group is capable of being bonded with the metal cation dangling bond.

A condensed cyclic compound represented by Formula 1:

##STR00001## wherein in Formula 1 groups and variables are the same as described in the specification.