An electrophotographic photoreceptor includes a conductive substrate; a photosensitive layer provided on the conductive substrate; and an undercoating layer that is provided between the conductive substrate and the photosensitive layer and includes a charge transport material containing at least one of imide compounds represented by Formula (1) or (2):

##STR00001## (in Formulas (1) and (2), R.sup.10, R.sup.11, R.sup.20, or R.sup.21 independently represents a group represented by Formula (3) or (4) where X represents a monovalent organic group having at least one of an alkyl group, an alkylene group, an ether group, an ester group, and a keto group, a halogen atom, a nitro group, an aralkyl group, or an aryl group, Y represents a sulfur atom or an oxygen atom, n represents an integer of 0 to 2, and when n represents 2, two X's may be the same or different), and an imide compound is represented by Formula (1A) where Ar represents an aromatic group having 6 to 18 carbon atoms except for a tetravalent perylene group, X.sup.1 and X.sup.2 each independently represent a nitrogen atom or a substituted or unsubstituted carbon atom, Y.sup.1 and Y.sup.2 each independently represent an oxygen atom, a sulfur atom, a selenium atom, or NH, and R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a monovalent organic group:

##STR00002##

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single-layer photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, a binder resin, and an additive. The additive contains a carboxylic acid anhydride. A reduction potential of the carboxylic acid anhydride is at least 1.40 V versus a reference electrode (Ag/Ag.sup.+). The carboxylic acid anhydride is contained in an amount of at least 0.02 parts by mass and no greater than 10.00 parts by mass relative to 100 parts by mass of the binder resin.

A compound of the general formula (I),

##STR00001##

a process for the production of the compound and its use in electronic devices, especially electroluminescent devices. Improved efficiency, stability, manufacturability, or spectral characteristics of electroluminescent devices are provided when the compound of formula I is used as host material for phosphorescent emitters in electroluminescent devices.

Compounds exhibiting high hole mobility and/or high glass transition temperatures together with favourable HOMO, LUMO and triplet levels are provided which are 2-(4-Diphenylamino)phenyl-8-(1-thianthrenyl)- dibenzothiophene and 4-(1-Thianthrenyl)-bis(triphenylamine). The compounds may be used for hole transport layers e.g. in OLED devices.

A compound of the general formula (I), ##STR00001##
a process for the production of the compound and its use in electronic devices, especially electroluminescent devices. Improved efficiency, stability, manufacturability, or spectral characteristics of electroluminescent devices are provided when the compound of formula I is used as host material for phosphorescent emitters in electroluminescent devices.

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single-layer photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, a binder resin, and an additive. The additive contains a carboxylic acid anhydride. A reduction potential of the carboxylic acid anhydride is at least 1.40 V versus a reference electrode (Ag/Ag.sup.+). The carboxylic acid anhydride is contained in an amount of at least 0.02 parts by mass and no greater than 10.00 parts by mass relative to 100 parts by mass of the binder resin.

An electrophotographic photoreceptor includes at least a photosensitive layer and a protective layer sequentially layered on a conductive support, wherein the protective layer contains a cured product of a curable composition containing p-type semiconductor fine particles, an n-type organic semiconductor, and a polymerizable compound.

An electrophotographic photoreceptor includes an intermediate layer, a photosensitive layer, and a surface layer laminated on a conductive support in this order, wherein a cured product of a polymerizable monomer contains an electron transport agent and n-type metal oxide fine particles to which a reactive organic group is bonded in the surface layer.

A compound of the general formula (I), a process for the production of the compound and its use in electronic devices, especially electroluminescent devices. Improved efficiency, stability, manufacturability, or spectral characteristics of electroluminescent devices are provided when the compound of formula I is used as host material for phosphorescent emitters in electroluminescent devices.

##STR00001##

A compound of the general formula ##STR00001##
a process for the production of the compound and its use in electronic devices, especially electroluminescent devices. Improved efficiency, stability, manufacturability, or spectral characteristics of electroluminescent devices are provided when the compound of formula I is used as host material for phosphorescent emitters in electroluminescent devices.