Electrical and interface state density properties of polyaniline–poly-3-methyl thiophene blend/p-Si Schottky barrier diode

• Published in: Solid state sciences Vol. 12; no. 5; pp. 706 - 711
• Main Authors: Sönmezoğlu, Savaş, Şenkul, Sevilay, Taş, Recep, Çankaya, Güven, Can, Muzaffer
• Format: Journal Article
• Language: English
• Published: Issy-les-Moulineaux Elsevier Masson SAS 01.05.2010; Elsevier Masson
• Subjects: Aluminum; Applied sciences; Barriers; Bias; Blends; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Density; Diodes; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronics; Exact sciences and technology; Ideality factor; Interface state density; Interfaces; Organic conducting polymer; Physics; Schottky barrier height; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Series resistance; Surface double layers, schottky barriers, and work functions; Thiophenes; Unity; Volt-ampere characteristics; Organic conducting polymer; Series resistance; Schottky barrier height; Ideality factor; Interface state density; Interfacial layer; Rectifier effect; Density of states; Voltage current curve; Thiophene; Energy level; Bias voltage; Silicon; Aniline polymer; Interface state; Interface energy; Electrical properties; Interface electron state; Energy density; Organic polymers; Electronic density of states; Conducting polymers; Acetonitrile; Barrier height; Schottky barrier diode; Schottky barrier
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2010.02.001

We have formed conjugated polymeric aniline–thiophene organic material on p-Si substrate by adding polyaniline–poly-3-methyl thiophene blend solution in acetonitrile on top of a p-Si substrate and then evaporating the solvent. It has been seen that the forward bias current–voltage ( I– V) characteristics of polyaniline–poly-3-methyl thiophene blend/p-Si/Al with a barrier height value of 0.60 eV and an ideality factor value of 3.37 showed rectifying behaviour at room temperature. The polyaniline–poly-3-methyl thiophene blend/p-Si/Al Schottky barrier diode showed non-ideal I– V behaviour with the value of ideality factor greater than unity that could be ascribed to the interfacial layer, interface states and series resistance. Furthermore, Cheung's functions and modified Norde's function were used to extract the diode parameters including ideality factor, barrier height and series resistance. It has been seen that there is a good agreement between the barrier height values from all methods. However, the values of series resistance obtained from Cheung's functions is higher than the values obtained from Norde's functions. The energy distribution of interface states density, determined from forward bias current–voltage ( I– V) characteristic technique at room temperature, increases exponentially with bias from 2.81 × 10 16 cm −2 eV −1 in (0.73– E v) eV to 1.14 × 10 17 cm −2 eV −1 in (0.48– E v) eV. [Display omitted]