Electrical properties of amorphous Se70Ge30-xMx system, where M represents silver, cadmium or lead
M.A. Afifi; M. Fadel; E. G. El-Metwally; A.M. Shakra;
Abstract
Current–voltage characteristics and DC electrical conductivity were measured for Se70Ge30 xMx (x ¼ 0; 5 and
M ¼ Ag,Cd or Pb) thin film samples as a function of temperature and thickness. DC conductivity increases with
temperature and with the addition of Ag,Cd or Pb, while it decreases with increasing film thickness. The observed
increase in conductivity with Pb is higher than that with Cd,which in turn is higher than that with Ag. The obtained
results showed that the conduction activation energy has two values DEs1 and DEs2 indicating the presence of two
different conduction mechanisms through the investigated range of temperature (308–453 K). Current–voltage curves of
the investigated samples are typical for a memory switch. The mean value of the threshold voltage Vth increases with
film thickness and decreases with increasing temperature in the range (308–403 K) and with the addition of Ag,Cd or
Pb. The obtained mean value (0.471) of the ratio =DEs2 (where is the threshold voltage activation energy) for the
investigated compositions agrees with the value of 0.5 obtained theoretically on the basis of an electrothermal model.
Moreover,the obtained values of DTbreakdown for most of the investigated compositions are in the same order with those
obtained before. Therefore the switching phenomenon in the investigated compositions can be explained according to
the electrothermal model.
M ¼ Ag,Cd or Pb) thin film samples as a function of temperature and thickness. DC conductivity increases with
temperature and with the addition of Ag,Cd or Pb, while it decreases with increasing film thickness. The observed
increase in conductivity with Pb is higher than that with Cd,which in turn is higher than that with Ag. The obtained
results showed that the conduction activation energy has two values DEs1 and DEs2 indicating the presence of two
different conduction mechanisms through the investigated range of temperature (308–453 K). Current–voltage curves of
the investigated samples are typical for a memory switch. The mean value of the threshold voltage Vth increases with
film thickness and decreases with increasing temperature in the range (308–403 K) and with the addition of Ag,Cd or
Pb. The obtained mean value (0.471) of the ratio =DEs2 (where is the threshold voltage activation energy) for the
investigated compositions agrees with the value of 0.5 obtained theoretically on the basis of an electrothermal model.
Moreover,the obtained values of DTbreakdown for most of the investigated compositions are in the same order with those
obtained before. Therefore the switching phenomenon in the investigated compositions can be explained according to
the electrothermal model.
Other data
Title | Electrical properties of amorphous Se70Ge30-xMx system, where M represents silver, cadmium or lead | Authors | M.A. Afifi; M. Fadel; E. G. El-Metwally ; A.M. Shakra | Keywords | Thin films;Conductivity;Temperature dependence;Chalcogenide | Issue Date | 15-Oct-2004 | Publisher | Elsevier | Journal | Vacuum | Volume | 77 | Start page | 259 | End page | 268 |
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