ABSTRACT

Our study of the defect physics in CuInSe2 showed that (i) it is much easier to form Cu vacancy than to form cation vacancy in II-VIs. (ii) defect formation energies vary considerably both with the Fermi energy and the chemical potential of the atomic species, and (iii) defect pairs such as (2VCu + InCu) have low formation energies in Cu-poor samples. These explain that (a) the existence of the ordered defect compounds in CuInSe2 is due to the formation of ordered array of https://www.w3.org/1998/Math/MathML"> 2 V C u − + I n C u 2 + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003063049/ea1329d3-df9d-47ef-98aa-cba26732e61c/content/ieq0232.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , (b) the efficient p-type self-doping is due to the exceptionally low formation energy of Cu vacancies and its very shallow energy levels, and (c) the electrically benign character for samples with large defect population is due to an electronic passivation of the deep levels, such as https://www.w3.org/1998/Math/MathML"> I n C u 2 + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003063049/ea1329d3-df9d-47ef-98aa-cba26732e61c/content/ieq0233.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , by its attraction to easily-formed https://www.w3.org/1998/Math/MathML"> V C u − https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003063049/ea1329d3-df9d-47ef-98aa-cba26732e61c/content/ieq0234.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Our calculated defect transition energy levels are in good agreement with the available experimental data.