Thermoelectric effect spectroscopy of deep levels in semi-insulating GaN

The report of thermoelectric effect spectroscopy (TEES) applied on semi-insulating GaN was presented. The type of TEES setup, especially suitable for film-on-substrate samples, was devised. TEES enabled determination of sign of observed deep traps. Using TEES and thermally stimulated current spectroscopy measurements in combination with the simultaneous multiple peak analysis formalism all important trap parameters were determined. The shallowest identified electron and hole traps had activation energies E-c-0.09 eV and E-v+0.167 eV, respectively. Results indicate that both these traps, oppositely charged are present in the studied material in relatively high concentrations causing the electrical compensation and high resistivity. (C) 2002 American Institute of Physics.