NOVELTY - A new polymer has a thermal-dissociation soluble group.    USE - New polymer is used in compositions used for forming organic layers of electronic devices e.g. solar-cell elements, organic layers e.g. light-emitting layers of organic electroluminescent elements used in display devices and illumination devices, and other organic-electroluminescent-element materials (all claimed) e.g. hole injection material, hole transport material, luminescent material, host material, electron injection material, and electron transport material. Can also be used for organic electrophotographic photoreceptors, transparent and colored resists of color filters, ribs, overcoats, and photospacers, organic insulating films, and organic thin-film-transistor materials. The organic electroluminescent element is used in light sources of copiers, backlights of LCDs and measuring instruments, display boards, marker lamps, flat panel displays of wall-mounted televisions, vehicle-mounted display devices, and mobile-telephone displays.    ADVANTAGE - The new polymer forms organic layers having excellent film stability, and provides luminescent materials having high driving stability and excellent charge transport efficiency. Since the polymer has a thermal-dissociation soluble group, the polymer can be made soluble in a coating solvent during wet film-formation. Since the thermal-dissociation soluble group dissociates by heat after film-formation, solubility over other coating solvents is reduced. Lamination of other organic layers by wet formation is possible. The polymer provides organic electroluminescent elements having excellent luminous efficiency and low drive voltage. The polymer provides solar-cell elements having excellent conversion efficiency.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) composition comprising the polymer and a solvent;    (2) organic electroluminescent element having an organic layer provided between an anode (2) and a cathode (9). The organic layer is formed by wet-forming method using the composition;    (3) solar-cell element having an organic layer provided between an anode and a cathode; and    (4) organic-electroluminescent material obtained by heating a compound having a partial structure in which thermal-dissociation soluble group is bonded with a hydrocarbon ring condensed with the aromatic-hydrocarbon ring or the aromatic heterocycle.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic sectional view of the organic electroluminescent element.    Substrate (1)    Anode (2)    Positive hole injection layer (3)    Light-emitting layer (5)    Cathode (9)