NOVELTY - A triangulene oligomer (I), is new.    USE - New triangulene oligomer (I) is used for dye-sensitized or perovskite-based photoelectric conversion device, solar cell, organic field-effect transistor, substrate, electroluminescent arrangement, organic solar cell, organic electronics application, organic light-emitting diode, organic photovoltaic cell, and bulk hetero-junction organic solar cell (all claimed).    ADVANTAGE - The new triangulene oligomer has excellent thermal stability and hole-conducting property.    DETAILED DESCRIPTION - A triangulene oligomer of formula (I), is new.    n=0-100;    X1,X2,X3,X4,X5=H, F, Cl, Br, I, CN, B(ORc)2, hydroxy, mercapto, nitro, cyanato, thiocyanato, formyl, acyl, carboxy, carboxylate, alkylcarbonyloxy, carbamoyl, alkylaminocarbonyl, dialkyla- minocarbonyl, sulfo, sulfonate, sulfoamino, sulfamoyl, alkylsulfonyl, aryl-sulfonyl, amidino, or NE1E2;    E1,E2=H, alkyl, cycloalkyi, heterocycloalkyl, aryl or hetaryl, in each case unsubstituted or substituted alkyl, alkoxy, alkylthio, (monoalkyl)amino, (dialkyl)amino, cycloalkyl, cycloalkoxy, cycloalkylthio, (monocycloalkyl)amino, (dicycloalkyl)amino, heterocycloalkyl, heterocycloalkoxy, heterocycloalkylthio, (monoheterocycloalkyl)amino, (diheterocycloalkyl)amino, aryl, aryloxy, arylthio, (monoaryl)amino, (diaryl)amino, hetaryl, hetaryloxy, hetarylthio, (monohetaryl)amino and (dihetaryl)amino;    Rc=optionally substituted alkyl, cycloalkyl or aryl, or wherein two radicals Rc optionally form a divalent bridging group chosen from optionally substituted 2-10C alkylene, 3-6C cycloalkylene and 6-14C arylene, in which 2-10C alkylene, 3-6C cycloalkylene and 6-14C arylene optionally carry one or more identical or different 1-12C alkyl radicals;    Ra, Rb=H or unsubstituted 1-6C alkyl;and    R,R2,R3,R4,R5,R6,R13,R14,R15,R16,R7,R8,R9,R10,R11, R12=H, optionally substituted alkyl, alkoxy, alkenyl, alkadienyl, alkynyl, cycloalkyl, cycloalkoxy, bicycloalkyl, cycloalkenyl, heterocycloalkyl, hetero- cycloalkyloxy, aryl, aryloxy, heteroaryl or heteroaryloxy.    INDEPENDENT CLAIMS are included for the following:    (1) composition, which comprises triangulene oligomer of formula (I);    (2) preparation of triangulene oligomer (I);    (3) solar cell, which comprises photoelectric conversion device;    (4) organic field-effect transistor, which comprises substrate having at least one gate structure, source electrode and drain electrode and triangulene oligomer (I) or composition as semiconductor material;    (5) substrate, which comprises several organic field-effect transistors;    (6) electroluminescent arrangement, which comprises an upper electrode, a lower electrode, in which at least one of electrodes is transparent, an electroluminescent layer and optionally an auxiliary layer, and comprises at least one triangulene oligomer (I) or composition; and    (7) use of a triangulene oligomer (I) as hole-transporting material (p-semiconductor) in dye-sensitized or in perovskite-based photoelectric conversion devices.