Electron Spin Resonance and Ultra Violet (UV) Photoluminescence of Ge Implanted CuGaSe2 Thin Films Prepared by the CCSVT (Chemical Close-spaced Vapor Transport) Technique

Abstract

AbstractNon-equilibrium ion implantation of Ge in p-type polycrystalline thin film CuGaSe2 (CGSe) prepared by Chemical Close-spaced Vapor Transport (CCSVT) has been performed with the goal to achieve n-type doping of this chalcopyrite semiconductor. Using Electron Spin Resonance (ESR) it is shown that Ge implantation induces a paramagnetic specie at g = 2.003. A model is proposed that assigns the ESR signal to electrons trapped by donor states that are electrically inactive. Moreover, UV photoluminescence of Ge implanted films has evidenced a new peak emission at 1.47 eV, which is resolved as a radiative recombination of a hole bound to the native copper vacancy and an electron bound to a deep donor with an ionization energy of ED =360±10 meV.