Study of deep hole and electron traps in nitrogen-doped ZnSe by isothermal capacitance transient spectroscopy and deep level transient spectroscopy

Abstract

Deep hole traps in N-doped p-type ZnSe epilayer grown by molecular-beam epitaxy have been studied using isothermal capacitance transient spectroscopy and deep level transient spectroscopy measurement (DLTS). Two hole traps with thermal activation energies of 0.68 and 0.85 eV were detected. These centers have large potential barrier heights in the carrier capture process. The thermal activation energies for the carrier capture were 0.23 eV on KT1 trap and 0.33 eV on KT2. These facts indicate that large lattice relaxation is induced in the hole capture/ emission processes. The deep electron trap related to active nitrogen doping was measured through comparison of the DLTS results from n-type ZnSe co-doped with chlorine and nitrogen with those from chlorine-doped n-type ZnSe. A deep electron trap associated with nitrogen doping with activation energy of 0.36 eV below the conduction band was found.