Physical Investigations on SnS/Ag Schottky Diodes

摘要

Ag/p-SnS Schottky diodes have been fabricated using thermal evaporation of SnS films. The layers were grown on Corning 7059 glass substrates at a temperature of 573 K. The current - voltage (Ⅰ-Ⅴ) characteristics of the diodes were measured at different temperatures that varied from 303 K to 423 K and the capacitance - voltage (C-V) studies were carried out at room temperature. The junction parameters such as diode ideality factor, barrier height and net carrier density were evaluated as 2.32, 0.42 eV and 4.15 x 10~(14) cm~(-3) respectively at room temperature. The barrier height of the junction increased with increasing temperature where as the ideality factor decreased. The low ideality factor indicates thermionic emission mechanism for Ag/p-SnS diodes at temperatures > 373 K although the diodes were clearly rectifying. The non-linearity of the Ⅰ-Ⅴ characteristics at low voltages indicates space-charge-limited conduction as the dominant current transport mechanism in the diodes. The C - V characteristics were also measured at room temperature and the junction parameters such as built-in potenatil, width of the depletion region, acceptor concentration and interface state density were evaluated.