High-temperature conductivity and copper solubility in CdS single crystals are measured as a function of temperature (350 to 1050 "C) and cadmium vapour pressure (10-12 to loo atm). A method of finding dominant defects is proposed, based on the experimental dependence of electron concentration and impurity solubility on cadmium vapour pressure. It is ascertained that copper dissolves in CdS in the form of electrically neutral complexes. Electrically charged defects occur as associates, consisting of substitutional and interstitial copper atoms. Quasi-chemical reactione (QCR) for forming these defects are proposed and their thermodynamic parameters are determined. HpOBeneHbl B MOHOKPMCTaJIJlaX CdS B 3aBHCMMOCTH OT TeMnepaTypbI (350 HO 1050 " c ) He@eHTOB, MCXOZIH 113 3KCIIepHMeHTaJILHbIX RaHHbIX 3aBHCHMOCTM KOHUeHTpaUMH ~~0 6 0~-HblX 3JIeKTPOHOB M PaCTBOpMMOCTH IlpHMeCH OT HaBJIeHHR IlapOB ICanMMR. YCTaHOBJIeHO, 9 T O MeHb PaCTBOpReTcH B CdS B OCHOUHOM B BMne 3JleKTpOHt?$~TpaJIbHbIX KOMnJIeKCOB. 3JIeKTpMTeCIEH 3apHWeHHbIe Ae@eKTbI RBJIFIIOTCH TaKlfFe aCCOUHaTaMH, COCTORIL[MWH M3 M3MepeHMH BblCOKOTeMnepaTypHOfi IIpOBOAMni OCTH H paCTBOPHMOCTH MenM M HaBJIeIIMtf napoB ICanMm ( no loo a m ) . IIpennomeH MeTon HaxomneIIm AOMHHM~YIOIUHX nienn a a~e w e~~~ M MexyaenbHbIx aToMoB nienti. IIpe~nomeabr K B~~H X H M H~I~C H H~ peawHM (KXP) 06pa30BaHHR BTMX ne@emos H onpenenem1 M X TepMonmaMasecmie IIapaMeTpbI.