An overview is presented of results obtained recently by my group on the effect of point defects on the conduction properties ofCu(In1−xGax)Se2.(CIGS) An interpretation of the data is presented suggesting that clustering of majority point defects into superclusters. This leads to uncompensated defects around the perimeter of the superclusters. These may account for one type of acceptor in the material. The other acceptor is proposed to beCuIn,a minority defect. It is suggested based on electrical results that Ga increases formation of defects. The observed compensating donor is proposed to be unpairedInCu.It is shown that these donors are removed by Na impurities. Finally, a discussion of ion implant damage is presented. It is argued that the mobility of holes in CIGS should be at least 100 cm2/V-s in good materials. ©1999 American Institute of Physics.