Temperature Dependent Electrical Transport in Al/Poly(4-vinyl phenol)/p-GaAs Metal-Oxide-Semiconductor by Sol-Gel Spin Coating Method

Şadan Özden,Osman Pakma,Cem Tozlu

doi:10.1155/2016/6157905

Abstract

Deposition of poly(4-vinyl phenol) insulator layer is carried out by applying the spin coating technique ontop-type GaAs substrate so as to create Al/poly(4-vinyl phenol)/p-GaAs metal-oxide-semiconductor (MOS) structure. Temperature was set to 80–320 K while the current-voltage (I-V) characteristics of the structure were examined in the study. Ideality factor (n) and barrier height (ϕb) values found in the experiment ranged from 3.13 and 0.616 eV (320 K) to 11.56 and 0.147 eV (80 K). Comparing the thermionic field emission theory and thermionic emission theory, the temperature dependent ideality factor behavior displayed that thermionic field emission theory is more valid than the latter. The calculated tunneling energy was 96 meV.

Highlights

Compound semiconductor materials can be used in such applications to achieve better results
Device performance is significantly affected by gate dielectric, which is an important component of organic thin film transistors (OTFT) [19]
Certain electrical instabilities are found in an OTFT with poly(4-vinyl phenol) used as the gate dielectric, a case which could be exemplified by bias stress effect or hysteresis, leading to shifting threshold voltage depending on the amount of hydroxyl groups and to gate leakage current

Summary

Introduction

Compound semiconductor materials can be used in such applications to achieve better results. The density of the amorphous phase declines due to these holes approximately by 10%, when compared to that of the crystalline phase of the same polymeric material Such free-volume holes found in a polymeric system influence the polymer’s optic, thermal, dielectric, electrical, and relaxing properties. For this reason, poly(4-vinyl phenol) is much more preferred as an insulating layer since it has several advantages such as higher device performance, stability, and reliability over other kinds of insulator layers. The current-applied bias voltagetemperature (I-V-T) measurement in darkness was performed to clarify the current transport mechanism(s) and electrical features of Al/poly(4-vinyl phenol)/p-GaAs structures. The sample temperature was continually monitored using a GaAlAs sensor and a Lakeshore 330 autotuning temperature controller with a sensitivity better than ±0.1 K

Measurement and Experimental Results

Findings

Conclusions