A light-emitting element having low driving voltage and high emission efficiency is provided. In the light-emitting element, a combination of a guest material and a host material forms an exciplex. The guest material is capable of converting triplet excitation energy into light emission. Light emission from the light-emitting layer includes light emission from the guest material and light emission from the exciplex. The percentage of the light emission from the exciplex to the light emission from the light-emitting layer is greater than 0 percent and less than or equal to 60 percent. The energy after subtracting the energy of light emission from the exciplex from the energy of light emission from the guest material is greater than 0 eV and less than or equal to 0.23 eV.

The application relates to a strongly-polarized molecule of the following general formula: wherein A denotes a group having a polarizability greater than 2 C.Math.m.sup.2/V; R.sub.1 and R.sub.2 are respectively hydrogen, halogen, a hydroxyl group, an amino group, a cyano group, a nitro group, a carboxyl group, a C.sub.1-12 alkyl group, a C.sub.1-12 alkoxy group, a halogenated C.sub.1-12 alkyl group, a halogenated C.sub.1-12 alkoxy group, a hydroxyl C.sub.1-12 alkyl group, a hydroxyl C.sub.1-12 alkoxy group, or a C.sub.1-12 alkyl amino group; x.sub.1 and x.sub.2 denote 0 or an integer no less than 1, respectively; and y.sub.1 and y.sub.2 denote 0 or an integer no less than 1, respectively. The application further relates to a strongly-polarized molecule-graphene molecule heterojunction, and a single molecule field effect transistor comprising a substrate, a gate, a dielectric layer and the strongly-polarized molecule-graphene molecule heterojunction; and the dielectric layer is located between the gate and the strongly-polarized molecule-graphene molecule heterojuction. The single molecule field effect transistor provided by the application can realize highly-efficient gate modulation.

##STR00001##

An organometallic compound represented by Formula 1:

M(L.sub.1).sub.n1(L.sub.2).sub.n2Formula 1 wherein groups M, L.sub.1, L.sub.2, n1, and n2 are the same as they are defined in the specification.

A compound comprising a first ligand L.sub.A having the formula ##STR00001##
Formula I, is disclosed. In Formula I, ring A is a five- or six-membered carbocyclic or heterocyclic ring; Y.sup.1 is selected from carbon and nitrogen; each of X.sup.1 to X.sup.4 is C or N; at least two adjacent R.sup.2s of ring B form a fused structure having the following formula: ##STR00002##
ring C is fused to ring B and the wavy lines are bonds attached to ring B; ring D and ring E are either a 5-membered aromatic ring or a 6-membered aromatic ring; each R.sup.1, R.sup.2, R.sup.3, R.sup.A, R.sup.B, R.sup.C, and R.sup.D is independently selected from a variety of substituents; ligand L.sub.A is coordinated to a metal M and, optionally, linked with other ligands; and M is optionally coordinated to other ligands. Organic light emitting devices and consumer products containing the compounds are also disclosed.

Disclosed herein is a compound of formula (I):

[M(L).sub.n].sup.m+(A.sup.y).sub.z(I)

where A, M, L, n, m, y and z are as defined herein, which can be used in the formation of a resistive memory device. Also disclosed herein are methods of manufacturing such devices and their uses.

The dye-sensitized solar cell comprises a first electrode including a porous semiconductor layer supporting a dye; and a second electrode serving as a counter electrode of the first electrode. The second electrode includes a counter electrode conductive layer containing an absorbent supporting a dye that is the same as or different from the dye supported by the porous semiconductor layer.

Emissive devices are provided that include a phosphorescent emitter placed within a threshold distance of an enhancement layer to achieve transient lifetimes of 200 ns or less.

A light-emitting element having low driving voltage and high emission efficiency is provided. In the light-emitting element, a combination of a guest material and a host material forms an exciplex. The guest material is capable of converting triplet excitation energy into light emission. Light emission from the light-emitting layer includes light emission from the guest material and light emission from the exciplex. The percentage of the light emission from the exciplex to the light emission from the light-emitting layer is greater than 0 percent and less than or equal to 60 percent. The energy after subtracting the energy of light emission from the exciplex from the energy of light emission from the guest material is greater than 0 eV and less than or equal to 0.23 eV.

An organic electroluminescence device material comprising a metal complex having a neopentyl group, for example, as shown below; and an organic electroluminescence device comprising a substrate having thereon a pair of electrodes and at least one organic layer between the electrodes, the organic layer containing a light emitting layer, wherein any one of the organic layer contains the organic electroluminescence device material.

##STR00001##

Disclosed are a series of photoisomeric compounds, preparation method therefor and device comprising the compounds. A photoisomeric compound-grephene molecular junction device is formed by linking the photoisomeric compound to a gap of two-dimensional monolayer graphene having a nano-gap array via an amide covalent bond. When a single photoisomeric compound is bridged to the gap of the two-dimensional monolayer graphene having a nano-gap array, the devices have a reversible light-controlled switching function and a reversible electrically-controlled switching function. A molecular switch device prepared by the method can achieve high reversibility and good reproducibility. The number of light-controlled switching cycles can exceed 10.sup.4, and the number of electrically-controlled switching cycles can reach about 10.sup.5 or greater. The reversible molecular switch device remains stable within a period of more than one year. Flexible non-losable organic memory transistor devices and light-responsive organic transistor devices can be constructed using the series of photoisomeric compounds.