Characterization of electrical transport and properties of an Al/porous Si (PS)/p-Si/Al heterojunction

In this paper is discussed the current transport characteristics of an Al/PS/p-Si/Al heterojunction device with a porous silicon layer (PS) fabricated by the electrochemical anodization process and its current transport properties are investigated by the using temperature dependent current-voltage (I-V) measurements in a wide temperature range from 50 K to 300 K. The electrical parameters are characterized with the thermionic emission theory. It is observed that the main characteristics such as ideality factor and apparent barrier height demonstrate resolute temperature dependences and this situation is related to the structure of porous region. In addition, it is obtained the conductance curves for the forward and reverse bias values of Al/PS/p-Si/Al sample and as a result, the value of the relative dielectric constant εr of porous layer is calculated as εr:3.72. From the reverse bias I-V curves, it is discussed the current conduction mechanism of porosity region by using Poole-Frenkel emission and Schottky emission. In result, it is commented that the charge transport in PS is through Poole-Frenkel conduction mechanism for Al/PS/p-Si/Al.