NOVELTY - Polymer comprising dithienobenzofuran repeating unit (I), is new.    USE - In the organic semiconductor material for electronic device selected from organic light emitting diode, organic photovoltaic device, organic field effect transistor, and photodiode (claimed) e.g. solar cell; light-emitting electrochemical cell (LEC); and organic laser diode. Also used in integrated circuits in various electronic articles e.g. radio-frequency identification (RFID) tags, backplanes for flexible displays, smart cards, memory devices, sensors, security devices.    ADVANTAGE - The polymer has excellent solubility in organic solvents and excellent film-forming properties; has high efficiency of energy conversion, excellent field- effect mobility, good on/off current ratios and excellent stability.    DETAILED DESCRIPTION - Polymer comprising dithienobenzofuran repeating unit of formula (I), is new.    R1 and R2=H, F, 1-18C alkyl (which is optionally substituted by E' and/or interrupted by D'), 6-24C aryl (which is optionally substituted by G'), 2-20C heteroaryl (which is optionally substituted by G');or    R1+R2=group of formula (i), (ii), or (iii);    R205, R206, R'206, R207, R208, R'208, R209 and R210=1-8C alkyl or 1-18C alkoxy (both optionally substituted by E' and/or interrupted by D'), 1-18C fluoroalkyl, 6-24C aryl (which is optionally substituted by G'), 2-20C heteroaryl (which is optionally substituted by G'), 2-18C alkenyl, 2-18C alkynyl, 7-25C aralkyl (which is optionally substituted by G'); CN, H or -CO-R28;    R601 and R602=H, halogen, 1-25C alkyl, 3-12C cycloalkyl, 2-25C alkenyl, 2-25C alkynyl, 6-24C aryl (which is substituted by G'), 7-25C aralkyl (which is optionally substituted by G');    D'=-CO-, -COO-, -S-, -SO-, -SO2-, -O-, -NR65-, -SiR70R71-, -POR72-, -CR63=CR64-, or -C?=C-;    E'=-OR69, -SR69, -NR65R66, -COR68, -COOR67, -CONR65R66, -CN, CF3, or halogen;    G'=1-18C alkyl (optionally interrupted by -O-) or E';    R28=H; 6-18C aryl (which is optionally substituted by 1-18C alkyl, or 1-18C alkoxy); 1-18C alkyl (which is optionally interrupted by -O-);    R63 and R64=6-18C aryl (optionally substituted by 1-18C alkyl, or 1-18C alkoxy); 1-18C alkyl; or 1-18C alkyl (which is interrupted by -O-);    R65 and R66=6-18C aryl (optionally substituted by 1-18C alkyl, or 1-18C alkoxy); 1-18C alkyl; or Ci-Cisalkyl which is interrupted by -O-;or    R65+R66=five or six membered ring;    R67=6-18C aryl (optionally substituted by 1-18C alkyl, or 1-18C alkoxy); or 1-18C alkyl (optionally interrupted by -O-);    R68=H; 6-18C aryl (which is optionally substituted by 1-18C alkyl, or 1-18C alkoxy); or 1-18C alkyl (which is optionally interrupted by -O-);    R69=6-18C aryl (which is optionally substituted by 1-18C alkyl, or 1-18C alkoxy); 1-18C alkyl (which is optionally interrupted by -O-);    R70 and R71=1-18C alkyl, or 6-18C aryl (which is optionally substituted by 1-18C alkyl);    R72=1-18C alkyl, or 6-18C-aryl (which is optionally substituted by 1-8C alkyl).    INDEPENDENT CLAIMS are included for the following:    (1) an organic semiconductor material, layer or component, comprising the polymer;    (2) an electronic device comprising the polymer, or the organic semiconductor material, layer or component; and    (3) preparation of the electronic device, involving applying a solution and/or dispersion of the polymer in an organic solvent to a suitable substrate and removing the solvent; or evaporation of the polymer.