The Au/n-Bi2Te3/psi/Al diode has been fabricated by using a thermal evaporation technique. The fabricated diodes were divided into two groups, the first group was as-fabricated diode, and the second group was irradiated by 6 MeV X-ray. The two groups were characterized by temperature dependent current-voltage (I-V) measurements in the range from 308 K to 373 K. The conduction mechanisms governed by the thermionic emission (TE) at lower forward voltages and the space charge-limited current (SCLC) dominated by single trap level at higher forward voltages. The junction parameters are estimated as a function of temperature. The junctions are non-ideal in showing ideality factor of 2.67 and 3.03 for as-fabricated and irradiated junctions at 308 K, respectively. The series resistances, rectification ratio and potential barrier height were also investigated.