Electrical properties of safranine T/p-Si organic/inorganic semiconductor devices

¹ Department of Physics, Faculty of Sciences and Arts, Batman University, 72060 Batman, Turkey
² Department of Physics, Faculty of Sciences and Arts, Dicle University, 21280 Diyarbakir, Turkey
³ Department of Physics, Faculty of Sciences, Atatürk University, 25240 Erzurum, Turkey

Corresponding author: omergullu@gmail.com

Received: 5 October 2009
Accepted: 5 January 2010
Published online: 26 February 2010

Abstract

We investigated the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of identically prepared safranine T/p-Si organic/inorganic Schottky devices (total 26 diodes) formed by evaporation of organic compound solution on p-Si semiconductor substrate. It was seen that the safranine T organic thin film on the p-Si substrate showed a good rectifying behavior. The barrier heights and ideality factors of all devices were extracted from the electrical characteristics. The mean barrier height and mean ideality factor from I-V measurements were calculated as 0.59±0.02 eV and 1.80±0.20, respectively. Also, the mean barrier height and mean acceptor doping concentration from C-V measurements were calculated as 0.67±0.10 eV and (6.96±0.37)×10¹⁴ cm^-3, respectively. The discrepancy in the barrier height values obtained from I-V and C-V characteristics has been attributed to different nature of the measurements. The discrepancy between these values can also be due to the existence of the interfacial native oxide and the organic safranine T thin layer between the semiconductor substrate and top contact metal.