Cu-63-NMR studies of crystalline and thin-film CuInSe2

Polycrystalline n- and p-type CuInSe2 (CIS) has been examined via Cu-63-NMR . Results show that a combination of interactions significantly affect the response including dipolar, quadrupolar and chemical shifts (possibly param agnetic + Knight shift). In order to separate the interactions, studies hav e been performed, at various frequencies on materials of different composit ion. These measurements are valuable since they provide information directl y related to the defect structure, and Cu+ migration in CIS. Most interacti ons have been modeled successfully. However, the origin of the temperature- dependent paramagnetic shift is suspected to be linked to carrier concentra tion but may arise from complex interactions between unpaired electron spin s at neighboring defect sires, One of the goals of this work is to ascertai n the degree by which nuclear magnetism is affected through intrinsic defec ts and conduction electrons. Such information is important for the characte rization of electronic properties and ultimately device performance. (C) 20 01 Elsevier Science B.V, All rights reserved.