NOVELTY - A polymer (P1) derived from a 9-((pentaphenyl)phenyl)carbazole structure, formed by a reaction between a compound with 9-((pentaphenyl)phenyl)carbazole structure, and at least one reactive monomer selected from 9H-carbazole compound, benzo(1,2,5)thiadiazole compound, 1,4-bis-((E)-styryl)-benzene compound, 9H-fluorene compound, substituted phenyl compound, 1,4-bis-trimethylsilanyl-benzene compound, and 2,2'-di(naphthalen-1-yl)biphenyl compound; is new.    USE - In organic solar cell device; and as hole injection material, hole transport material, emitting material, or host material in organic electroluminescence device and/or phosphorescence device (claimed). The organic electroluminescence device and/or phosphorescence devices include organic electroluminescent displays (OEL display)/organic light emitting diode displays.    ADVANTAGE - The polymer derived from 9-((pentaphenyl)phenyl)carbazole structure provides improved polymeric material for polymer organic light emitting diode displays or organic electroluminescent displays (OEL display) by exhibiting good thermal stability; where for the small molecule dye, pigment, or polymeric light emitting materials, hole injection materials, and hole transport materials, the common drawback is that the glass transition temperature is too low, in which since the OEL device produces excess joule heat during operating for a long period of time, operating temperature of device generally exceeds glass transition temperature (Tg) of the material so as to cause the material to recrystallize and to result in brightness decay and shortened lifetime. In the OEL displays comprising the polymeric material (P1) with good thermal stability utilization lifetime can be prolonged and luminance efficiency can be increased. The polymer electroluminescent material (P1) comprises the 9-((pentaphenyl)phenyl)carbazole, as a major substance; together with fluorene having a long alkyl side chain and carbazole as monomers, polymerized by such as Suzuki coupling, or Horner-Wadsworth-Emmons (HWE) reactions. Further, 1,4-bis(2-bromostyryl)benzene (OPV) and benzothiazole are introduced into the polymeric material to improve the optical and electrical property of the polymers. In the polymer, the (pentaphenyl)phenyl group side chain structure increases the steric effect of polymers so as to reduce molecular symmetry and reduce molecular chain aggregation, which prevents from being over red-shifted in fluorescence. On the other hand, the (pentaphenyl)phenyl group side chain structure makes the rotational degree of freedom decreased. Hence, the glass transition temperature of the polymer (P1) is higher than that of the general carbazole polymer, and the polymer has excellent thermal stability. Thus, the OEL displays comprising the polymer (P1) have the economic advantages for industrial applications.    DETAILED DESCRIPTION - A polymer (P1) derived from a 9-((pentaphenyl)phenyl)carbazole structure, formed by a reaction between a compound with 9-((pentaphenyl)phenyl)carbazole structure of formula (I), and at least one reactive monomer selected from 9H-carbazole compound of formula (IIa), benzo(1,2,5)thiadiazole compound of formula (IIb), 1,4-bis-((E)-styryl)-benzene compound of formula (IIc), 9H-fluorene compound of formula (IId) or (IIe), phenyl compound of formula (IIf), 1,4-bis-trimethylsilanyl-benzene compound of formula (IIg), and 2,2'-di(naphthalen-1-yl)biphenyl compound of formula (IIh); is new.    G1 and G2=H, carboxyl, hydroxyl, amino, double bond, triple bond, halo, -C(=O), -CH2-P(OR')2(=O), -B(OR')2, group of formula (i), or -Ar-G3;    R'=H, alkyl, or aryl;    Ar=aryl;    G3=H, carboxyl, hydroxyl, amino, double bond, or triple bond;    R1, R2, R3, R4, and R5=alkyl, or aryl;    G4=halo, -B(OR')2, group of formula (i), -C(=O), -CH2-P(OR')2(=O), carboxyl, hydroxyl, amino, double bond, or triple bond.