Temperature Dependent Current-Voltage Characteristics of n-Type Nanocrystalline-FeSi_2/p-Type Si Heterojunctions Fabricated by Pulsed Laser Deposition

摘要

n-Type NC-FeSi_2/p-type Si heterojunctions were successfully fabricated by PLD, and their forward current-voltage characteristics were analyzed on the basis of thermionic emission theory (TE) in the temperature range from 300 Down to 77 K. With a decrease in the temperature, the ideality factor was increased while the zero-bias barrier height was decreased. The calculated values of ideality factor and barrier height were 3.07 and 0.63 eV at 300 K and 10.75 and 0.23 eV at 77 K. The large value of ideality factor indicated that a tunneling process contributes to the carrier transport mechanisms in the NC-FeSi_2 films. The series resistance, which was estimated by Cheung's method, was strongly dependent on temperature. At 300 K, the value of series resistance was 12.44 Ω, and it was dramatically enhanced to be 1.71 ×10~5 Ω at 77 K.