An aspect of the present disclosure is a method that includes combining a first organic salt (A.sup.1X.sup.1), a first metal salt (M.sup.1(X.sup.2).sub.2), a second organic salt (A.sup.2X.sup.3), a second metal salt (M.sup.2Cl.sub.2), and a solvent to form a primary solution, where A.sup.1X.sup.1 and M.sup.1(X.sup.2).sub.2 are present in the primary solution at a first ratio between about 0.5 to 1.0 and about 1.5 to 1.0, and A.sup.2X.sup.3 to M.sup.2Cl.sub.2 are present in the primary solution at a second ratio between about 2.0 to 1.0 and about 4.0 to 1.0. In some embodiments of the present disclosure, at least one of A.sup.1 or A.sup.2 may include at least one of an alkyl ammonium, an alkyl diamine, cesium, and/or rubidium.

A method for depositing a conductive coating on a surface is provided, the method including treating the surface by depositing fullerene on the surface to produce a treated surface and depositing the conductive coating on the treated surface. The conductive coating generally includes magnesium. A product and an organic optoelectronic device produced according to the method are also provided.

A method for preparing photoactive perovskite materials. The method comprises the step of preparing a germanium halide precursor ink. Preparing a germanium halide precursor ink comprises the steps of: introducing a germanium halide into a vessel, introducing a first solvent to the vessel, and contacting the germanium halide with the first solvent to dissolve the germanium halide. The method further comprises depositing the germanium halide precursor ink onto a substrate, drying the germanium halide precursor ink to form a thin film, annealing the thin film, and rinsing the thin film with a second solvent and a salt.

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 method for depositing a conductive coating on a surface is provided, the method including treating the surface by depositing fullerene on the surface to produce a treated surface and depositing the conductive coating on the treated surface. The conductive coating generally includes magnesium. A product and an organic optoelectronic device produced according to the method are also provided.

A tandem photovoltaic device includes a silicon photovoltaic cell having a silicon layer, a perovskite photovoltaic cell having a perovskite layer, and an intermediate layer between a rear side of the perovskite photovoltaic cell and a front (sunward) side of the silicon photovoltaic cell. The front side of the silicon layer has a textured surface, with a peak-to-valley height of structures in the textured surface of less than 1 μm or less than 2 μm. The textured surface is planarized by the intermediate layer or a layer of the perovskite photovoltaic cell. Forming the tandem photovoltaic device includes texturing a silicon containing layer of a silicon photovoltaic cell and operatively coupling a perovskite photovoltaic cell comprising a perovskite layer to the silicon photovoltaic cell, thereby forming a tandem photovoltaic device and planarizing the textured surface of the silicon containing layer of the silicon photovoltaic cell.

A radiation detector includes a halide semiconductor sandwiched a cathode and an anode and a buffer layer between the halide semiconductor and the anode. The anode comprises a composition selected from: (a) an electrically conducting inorganic-oxide composition, (b) an electrically conducting organic composition, and (c) an organic-inorganic hybrid composition. The buffer layer comprises a composition selected from: (a) a composition distinct from the composition of the anode and including at least one other electrically conducting inorganic-oxide composition, electrically conducting organic composition, or organic-inorganic hybrid composition; (b) a semi-insulating layer selected from: (i) a polymer-based composition; (ii) a perovskite-based composition; (iii) an oxide-semiconductor composition; (iv) a polycrystalline halide semiconductor; (v) a carbide, nitride, phosphide, or sulfide semiconductor; and (vi) a group II-VI or III-V semiconductor; and (c) a component metal of the halide-semiconductor.

An infrared absorption composition includes a p-type semiconductor compound including a first structural unit represented by Chemical Formula 1 and a second structural unit including an electron donating moiety; and an n-type semiconductor compound represented by Chemical Formula 2:

##STR00001## wherein, in Chemical Formula 1, Ar.sup.1, X, R.sup.1a, and R.sup.2a are the same as defined in the detailed description. In Chemical Formula 2, A.sup.1, A.sup.2, D.sup.1, D.sup.2, and D.sup.3 are the same as defined in the detailed description.

A method of manufacturing an optoelectronic device including the following successive steps: a) forming, on an integrated control circuit previously formed inside and on top of a semiconductor substrate, a plurality of inorganic light-emitting diodes; and b) depositing an active photosensitive semiconductor layer to fill free spaces laterally extending between the inorganic light-emitting diodes.

An OLED panel may be embedded with a near-infrared organic photosensor and may be configured to implement biometric recognition without an effect on an aperture ratio of an OLED emitter. The OLED panel may include a substrate, an OLED stack on the substrate and configured to emit visible light, and an NIR light sensor stack between the substrate and the OLED stack and including an NIR emitter configured to emit NIR light and an NIR detector. The OLED panel may be included in one or more various electronic devices.