NOVELTY - Copper(I) complex (I) is new.    USE - (I) is useful as an emitter and absorber in an optoelectronic component (including organic light-emitting devices (OLEDs), light-emitting electrochemical cells, OLED sensors, preferably in non-hermetically outwardly shielded gas and vapor sensors, organic solar cells, organic field effect transistors, organic lasers, down-conversion elements, organic diode and organic transistor); and in changing emission- and/or absorption characteristics of electronic component (all claimed).    ADVANTAGE - (I) has high emission quantum yield.    DETAILED DESCRIPTION - Copper(I) complex of formula (I) is new.    X1 = Cl, Br, I, CN, OCN, SCN, N3 or alkynyl;    Nasterisk-G1-E1 = a divalent ligand;    E1 = phosphanyl, arsenyl, antimonyl (optionally substituted with R1);    R1 = alkyl, aryl, heteroaryl, alkoxyl, phenoxyl or amide;    Nasterisk = imine function which is the part of an aromatic group, preferably pyridyl, pyridazinyl, pyrimidyl, pyrazinyl, triazinyl, tetrazinyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, 1,2,4-oxadiazolyl, 1,2,4-thiadiazolyl, tetrazolyl, 1,2,3,4-oxatriazolyl, 1,2,3,4-thiatriazolyl, quinolyl, isoquinolyl, quinoxalyl or quinazolyl (all optionally further substituted and/or fused);    ring G1 = at least one carbon atom which is also part of the aromatic group, where at least one carbon atom is situated directly adjacent to the imine nitrogen atom and P, Ar or Sb;    (R)2D1-B1-D1(R)2 = bidentate ligand;    D1 = P, As or Sb;    bridge B1 = alkylene, alkenylene, alkynylene, arylene (all optionally substituted), -O-, -NR- or -Si(R)2-;    R = M or L;    M = H, D or halo; and    L = alkyl, heteroalkyl, aryl, heteroaryl, alkenyl (all optionally substituted with halo, D, alkyl, heteroalkyl, aryl or heteroaryl), alkynyl, amines, carboxylates and their esters or CF3.    Provided that optional Nasterisk-G1-E1 and/or (R)2D1-B1-D1(R)2 have at least one substituent to improve charge carrier transport and/or to increase solubility of the copper(I) complex in an organic solvent; D2 binds to M directly and bind to L via O, N, Si or S; and at least two adjacent R are optionally fused together to form fused ring systems. INDEPENDENT CLAIMS are also included for:    (1) preparing (I);    (2) an optoelectronic component comprising (I), preferably formed as a component including organic light component, organic diode, organic solar cell, organic transistor, organic light-emitting diode, light-emitting electrochemical cell, organic field effect transistor or organic laser;    (3) a light-emitting material, comprising (I) and a host material, where the triplet (T1)- and singlet (S1)-energy levels of the host material are higher in energy than the triplet (T1)- and singlet (S1)-energy levels of (I), the light emitting material emits fluorescence or thermally activated delayed fluorescence and Delta E(S1-T1) value between the lowest excited singlet (S1)- and the underlying triplet (T1)-state is less than 2000 cm-1;    (4) producing the optoelectronic component, comprising applying (I) to a support by wet-chemical method using colloidal suspension or sublimation; and    (5) changing emission- and/or absorption characteristics of an electronic component, comprising introducing (I) in a matrix material for conducting electrons or holes in an optoelectronic component.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the optoelectronic component in the form of organic light-emitting diode.    Anode (2)    Hole injection layer (3)    Hole transport layer, (4)    Hole blocking layer (7)    Electron transport layer (8)