NOVELTY - A compound semiconductor particles composition contains particles (A) formed from several semiconductor particles consisting of chalcopyrite-type compound semiconductor and having number average particle size of 100 nm or more, and filler (B) formed using particles (BX) consisting of several semiconductor particles and having number average particle size less than that of particles (A) and/or non-solid semiconductor precursor composition (BY) capable of forming solid semiconductor by heating.    USE - Compound semiconductor particles composition is used for manufacturing compound semiconductor film used for photoelectric conversion element of solar cell (all claimed), optical sensor, image sensor and photodiode.    ADVANTAGE - The compound semiconductor particles composition increases photoelectric conversion efficiency of compound semiconductor film.    DETAILED DESCRIPTION - A compound semiconductor particles composition contains particles (A) formed from several semiconductor particles consisting of chalcopyrite-type compound semiconductor and having number average particle size of 100 nm or more, and filler (B) formed using particles (BX) consisting of several semiconductor particles and having number average particle size less than that of particles (A) and/or non-solid semiconductor precursor composition (BY) capable of forming solid semiconductor by heating. The number average particle size is measured by transmission electron microscope. The chalcopyrite-type compound semiconductor has compositional formula: LMX2, where L is IB group element, M is IIIB group element and X is VIB group element. INDEPENDENT CLAIMS are included for the following:    (1) compound semiconductor film (13);    (2) manufacture of compound semiconductor film; and    (3) photoelectric conversion element (10).    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic cross-sectional view of photoelectric conversion element.    Photoelectric conversion element (10)    Substrate (11)    Compound semiconductor film (13)    Buffer layer (14)    Heat-resistant layer (15)