NOVELTY - A benzimidazolo-benzothiazole derivative (I) is new.    USE - New benzimidazolo-benzothiazole derivative is used in charge transport layer, charge/exciton blocker layer and emitting layer of electronic device e.g. electroluminescent device for apparatus e.g. stationary visual display unit, mobile visual display unit, illumination unit, keyboard, clothing, furniture and wallpaper, electrophotographic photoreceptor, photoelectric converter, organic solar cell, switching element, organic light-emitting field effect transistor, image sensor and dye laser (all claimed).    ADVANTAGE - The electroluminescent device obtained using the benzimidazolo-benzothiazole derivative has high efficiency, and excellent stability, manufacturing efficiency and spectral characteristics.    DETAILED DESCRIPTION - A benzimidazolo-benzothiazole derivative of formula (I) is new.    Y1,Y2=1-25C alkyl (optionally substituted by E and/or interrupted by D'), or 6-24C aryl, 2-30C heteroaryl or 7-25C aralkyl (all optionally substituted by G);    c,d=0 or 1;    R1,R6=1-25C alkyl (optionally substituted by E and/or interrupted by D'), -(A1)o(A2)p-(A3)q-(A4)r-R16, or 6-24C aryl or 2-30C heteroaryl (both optionally substituted by G);    a,b=0-3;    o,p,q,r=0 or 1;    A1-A4=6-24C arylenyl, or 2-30C heteroarylenyl (both optionally substituted by G);    R16=H, -NR10R11, -Si(R12)(R13)(R14), or 6-24C aryl or 2-30C heteroaryl (both optionally substituted by G);    R10,R11=6-24C aryl or 2-30C heteroaryl (both optionally substituted by G);    R12-R14=1-25C alkyl (optionally substituted by E and/or interrupted by D'), or 6-24C aryl or 2-30C heteroaryl (both optionally substituted by G);    D'=-CO-, -COO-, -S-, -SO-, -SO2-, -O-, -NR65-, -SiR70R71-, -POR72-, -CR63=CR64- or -CC-;    E=-OR69, -SR69, -NR65R66, -COR68, -COOR67, -CONR65R66, -CN or F;    G=E, or 1-18C alkyl, 6-24C aryl (optionally substituted by F or 1-18C alkyl (optionally substituted by F and/or interrupted by O)), or 2-30C heteroaryl (optionally substituted by F, 1-18C alkyl (optionally interrupted by O) or -Si(R12')(R13')(R14'));    R12'-R14'=1-25C alkyl optionally interrupted by O, or 6-14C aryl or 2-10C heteroaryl (both optionally substituted by 1-18C alkyl);    R63,R64=H, 6-18C aryl (optionally substituted by 1-18C alkyl or 1-18c alkoxy), or 1-18C alkyl (optionally interrupted by -O-);    R65,R67,R69=6-18C aryl or 1-18C alkyl;    R68=H, 6-18C aryl or 1-18C alkyl;    R70,R71=1-18C alkyl or 6-18C aryl;and    R72=1-18C alkyl, or 6-18C aryl.    (i) At least one of R1 and R6 is -(A1)0-(A2)p-(A3)q-(A4)r-R16; and (ii) R16 is not H, when o, p, q and r are 0. Full Definitions are given in the "DEFINITIONS - Full Definitions" section. An INDEPENDENT CLAIM is included for charge transport layer, charge/exciton blocker layer, or emitting layer, which comprises benzimidazolo-benzothiazole derivative (I).