NOVELTY - Quinoxaline compound (I) is new.    USE - The compound (I) is useful: in organic solar cells as an exciton blocker or electron transport layer; in an organic light-emitting diode as an electron transport layer or emitter matrix; and in organic thin-layer transistor. The organic semiconductor material is useful in an organic light-emitting diode, organic thin-layer transistor and in organic solar cells for increasing the long-term stability and/or improving the short circuit strength, where the compound (I) is n-organic doped and is present in a layer construction, in which all materials of the layers exhibit a glass transition temperature of greater than or equal to 85 degrees C. The p-n-transition is useful: in an electronic; optoelectronic or electroluminescent device (all claimed).    ADVANTAGE - The matrix material comprising the compound (I) exhibits an improved conductivity, high thermal stability, reduced drive voltage and a lower diffusion of dopants that are introduced into the matrix material. The matrix material doped with the metal complex increases the power efficiency of the light-emitting diodes, thin film transistors and the solar cells. The organic semiconductor material increases the long-term stability and/or improves the short circuit strength.    DETAILED DESCRIPTION - Quinoxaline compound of formula (I) is new.    M = Ti, Zr, Hf, Nb, Re, Sn or Ge; and    R = H, 1-20C-alkyl, preferably methyl, 1-20C alkenyl, 1-20C alkynyl, aryl, heteroaryl, oligoaryl, oligoheteroaryl, oligoarylheteroaryl, -ORx, -NRxRy, -SRx, -NO2, -CHO, -COORx, -halo, -CN, -NC, -SCN, -OCN, -SORx or -SO2Rx or part of a condensed ring system; and    Rx, Ry = 1-20C-alkyl, 1-20C alkenyl or 1-20C alkynyl.    INDEPENDENT CLAIMS are also included for:    (1) an organic semiconductor material comprising at least one organic matrix material that is doped with at least one dopant, where the matrix material is (I); and    (2) a p-n-transition, where the transistion takes place at its n-side of the quinoxaline compound (I) in an electron transport layer and/or the quinoxaline compound (I) in an intermediate layer between the p-side and n-side.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic sectional view of an organic light emitting diode.    Substrate (10)    Anode (11)    Electron blocker (13)    Emission layer (14)    Cathode (17)