The investigation of current-transport mechanisms (CTMs) in the Al/(In2S3:PVA)/p-Si (MPS)-type Schottky barrier diodes (SBDs) at low and intermediate temperatures

Abstract

The current-transport mechanisms (CTMs) and temperature sensitivities (S) of the Al/(In2S3-PVA)/p-Si SBDs have been investigated using I-V measurements between 80 and 320 K. The logI(F)-V-F curves show two linear parts in the forward bias region and saturation current (I-o), ideality factor (n), barrier height (phi(BO)), and tunneling parameter (E-oo) values were calculated for each linear parts. It was observed that while phi(Bo) increased with increasing temperature, n decreased, leading to non-linearity in the Richardson plot and a very low Richardson constant (A*). To explain the higher n and lower phi(Bo) values at low temperatures, phi(Bo)-q/(2kT), phi(Bo)-n, and n.(kT)/q-(kT/q) plots were drawn to find evidence for Gaussian distribution (GD), tunneling (field and thermionic field: FE and TFE) mechanisms. These results show that both the double GD of BHs and tunneling are effective CTMs rather than the other both at low and moderate bias regions (LBR, MBR). The reverse bias ln(I-R)-(V-R)(0.5) plots show good linear behavior and the slope of them indicates that while Schottky emission (SE) dominates at high temperature, Poole-Frenkel emission (PFE) dominates at low temperatures, respectively. The energy-dependent profile of surface states (N-ss) was obtained using the Card-Rhoderick method and decreases as the temperature increases due to their reordering and reconstruction. The value of S for 0.1 mu A, 0.3 mu A, and 1 mu A were computed using the slope of V-T plots as - 0.90, - 0.98, - 1.02 mV/K at low temperatures and - 2.30, - 2.60, - 4.3 mV/K at high temperatures.