On the profile of temperature dependent main electrical parameters in Al/P3HT/p-Si (MPS) structures at low temperatures

Abstract

Abstract In order to good interpret the conduction mechanism in the Al/P3HT/p-Si (MPS) structure, both the capacitance-voltage (C-V), and conductance-voltage (G/ω-V) characteristics of the structure are carried out in the wide temperature (120-300 K) and voltage (±5 V by 50 mV steps), respectively. The C-V plot shows a peak behavior in the accumulation region for each temperature due to the presence of Rs and interfacial layer. When the value of C starts to decrease in the accumulation region, G/ω starts to increase due to inductive behavior of the sample. The obtained barrier height from the reverse bias C-2 vs V plot decreases with increasing temperature as linearly and has -3.68x10-4 eV/K negative temperature coefficient which is very closed to temperature coefficient of Si band-gap (-4.73x10-4 eV/K). The value of activation energy (Ea) was obtained from the slope of Arrhenius plot for various bias voltages and it changed from 5.75 eV (for 2 V) and 4.1 eV (for 5 V), respectively. In addition both the temperature dependent profile of Nss and Rs were obtained by using the Hill-Coleman and Nicollian-Brews methods, respectively, and they decrease with increasing temperature due to reordering and restructure of the surface charges under temperature and electric field. In order to see the effect of Rs on the C-V and plot G/ω-V plots, they were corrected. All experimental results were confirmed that the Rs, interfacial polymer layer, Nss and temperature are more effective on the conduction mechanism especially at low temperature