The Investigation of Current-Conduction Mechanisms of Te/NaF:CdS/SnO2 Structure in Wide Temperature Range of 80-400 K


Sevgili O., YILMAZ Ş., Altmdal S., BACAKSIZ E. , Bilkan C.

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES INDIA SECTION A-PHYSICAL SCIENCES, cilt.87, sa.3, ss.409-417, 2017 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 87 Konu: 3
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1007/s40010-017-0366-5
  • Dergi Adı: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES INDIA SECTION A-PHYSICAL SCIENCES
  • Sayfa Sayıları: ss.409-417

Özet

In order to interpret the current-conduction mechanisms of the Te/NaF: CdS/SnO2 structure, currentvoltage (I-V) measurements were carried out in the temperature range of 80-400 K. Experimental results show that the main electrical parameters such as reverse-saturation current (I-0), ideality factor (n) and zero-bias barrier height (phi(B0)) values were found to be strong functions of temperature. The I-0, n and phi(B0) values were found as 3.16 x 10(-12) A, 17.84 and 0.232 eV at 80 K and 2.85 x 10(-7) A, 1.40 and 0.877 eV at 400 K, respectively. Therefore, we have attempted to draw phi(B0) versus q/2kT plot in order to obtain the evidence of a Gaussian distribution of the barrier heights (BHs) and this plot shows two straight lines with different slopes. From these plots, mean BH ((phi) over bar (B0)) = 0: 673 eV and zero-bias standard deviation (sigma(s)) = 0.079 V in the first region (80-170 K), (phi) over bar (B0) = 1: 279 eV and sigma(s) = 0.160 V in the second region (200-400 K) have been obtained, respectively. The values of Richardson constant (A*) were obtained from the modified Richardson plot as 21.43 A cm(-2) K-2 (200-400 K) and 16.07 A cm(-2) K-2 (80-170 K), respectively. This 21.43 A cm(-2) K-2 value of A* for the first region is in very close agreement with the known theoretical value of 23 A cm(-2) K-2 for n-type CdS. It has been concluded that the temperature dependent I-V characteristics of the Te/NaF: CdS/SnO2 structure can be successfully explained by the basis of thermionic emission mechanism with double Gaussian distribution of the BHs rather than other mechanisms.