Photoconductivity and photoluminescence studies in copper diffused InP

Abstract

Cu diffusion was carried out in p-InP at 300°C for one hour followed by 600° C for one minute. High photoconductivity (Iph/Id = 2.6 × 10⁵ at 200K) was observed in this sample. Information about Cu related deep levels was obtained from dark conductivity, photoconductivity and its spectral response. A Cu related photoluminescence (PL) band was observed at 1.216 eV and its line-shape and line-width analysis carried out. The configuration coordinate diagram of the band was calculated and showed small lattice relaxation. In n-InP Cu diffusion at 650°C for two hours resulted in two PL bands at 1.20 and 1.01 eV. The former was similar to the 1.216 eV band in p-InP. The PL of the 1.01 eV band was also studied in detail and the corresponding configuration coordinate diagram derived. The parameters of the Cu related bands obtained from the line-shape and line-width analysis are compared with those reported due to Mn and Fe in InP.