CURRENT-VOLTAGE CHARACTERISTICS OF ELECTRIC CONTACTS ON P-TYPE ZNSE

The current-voltage characteristics of electric contacts made of diffe rent materials on p-type ZnSe that form Schottky barriers from 0.3 to 1.2 eV are studied theoretically using the formula J=AT/k integral-in finity/0T(E)[F(E) - F(E - eV)]dE, where T(E) is the energy-dependent q uantum tunneling probability and F(E) is the Fermi distribution functi on. The contribution to the total current of both the thermionic emiss ion and the tunneling are therefore included. The net doping concentra tions under study range from 1.0 x 10(17) cm-3 to 1.0 x 10(19) cm-3. T he reverse bias voltage across the barrier at a current density of 200 A/cm2 is used to assess whether the barrier is reduced to an ohmic co ntact. A barrier of 0.3 eV is already an ohmic contact at doping conce ntration p = 1.0 x 10(17) cm-3, while a barrier of 1.2 eV still behave s like a diode even at p = 1.0 x 10(19) cm-3.