NOVELTY - Substituted 1,3,6,8-Tetraaza-pyrene compounds are new.    USE - For forming thin film semiconductor, which is useful for preparing field effect transistor device, photovoltaic device, organic light emitting diode device, unipolar or complementary circuit device (claimed), photodetectors, capacitors, sensors, and solar cells.    ADVANTAGE - The compounds are organic n-type semiconducting compounds, having desirable properties such as air stability, high charge transport efficiency, and good solubility in common solvents. Thus, are suitable in inexpensive and large-area organic electronics that can be produced by high-throughput reel-to-reel manufacture, and can address various deficiencies and shortcomings of state-of-the-art. The tetraazapyrene compounds have semiconducting activity. The compounds have high carrier mobility and/or good current modulation characteristics in field-effect devices (e.g. thin-film transistors). In addition, the compounds possess certain processing advantages compared to related representative compounds, such as better solubility to permit solution-processability and/or good stability at ambient conditions e.g. air stability. Further, the compounds can be embedded with other components for utilization in variety of semiconductor-based devices. As the compounds are soluble in common solvents, they offer processing advantages in fabricating electrical devices such as thin film semiconductors, field-effect devices, organic light emitting diodes, organic photovoltaics, photodetectors, capacitors, and sensors. The compounds exhibit broad optical absorption and/or very positively shifted reduction potential making them desirable for such applications, and thus are useful in photovoltaic devices and solar cells.    DETAILED DESCRIPTION - Substituted 1,3,6,8-tetraaza-pyrene compounds of formula (I) are new.    R1, R2, R3 and R4=H, 1-30C alkyl, 1-30C alkoxy, 1-30C alkylthio, 6-14C aryl, 6-14C aryloxy, 6-14C arylthio, 7-20C arylalkyl, Cl or Br;    R5 and R6=6-14C aryl, 7-20C arylalkyl (both optionally substituted by at least one of halo, 1-4C haloalkyl, CN, NO2, CHO, COOH, CONH2, -CO(1-14C-alkyl), -COO(1-14C-alkyl), -CONH(1-14C-alkyl), and -CON(1-14C-alkyl)2); H, or 1-30C (halo)alkyl.    Provided that: at least one of R1, R2, R3, R4 is 6-14C aryloxy, 6-14C arylthio, Cl, or Br. An INDEPENDENT CLAIM is included for process for preparation of the compound (I).