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/omega-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 R-s and interfacial layer. When the value of C starts to decrease in the accumulation region, G/omega 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 (E-a) 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 N-ss and R-s 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 R-s on the C-V and plot G/omega-V plots, they were corrected. All experimental results were confirmed that the R-s, interfacial polymer layer, N-ss and temperature are more effective on the conduction mechanism especially at low temperature. (C) 2019 Elsevier Ltd. All rights reserved.