Synthetic Metals 142 (2004) 177–180 The Schottky barrier height of the rectifying Cu/pyronine-B/p-Si, Au/pyronine-B/p-Si, Sn/pyronine-B/p-Si and Al/pyronine-B/p-Si contacts M. Çakar a , C. Temirci b , A. Türüt c,∗ a Department of Chemistry, Faculty of Sciences and Arts, University of Kahramanmara¸ s Sütçü ˙ Imam, Kahramanmara¸ s , Turkey b Department of Physics, Faculty of Sciences and Arts, Yüzüncü Yıl University, Van, Turkey c Department of Physics, Faculty of Arts and Sciences, Atatürk University, Erzurum, Turkey Received 20 July 2003; accepted 24 August 2003 Abstract The Cu/pyronine-B/p-Si, Au/pyronine-B/p-Si, Al/pyronine-B/p-Si and Sn/pyronine-B/p-Si Schottky structures have been obtained by sublimation of the organic compound pyronine-B onto the top of p-Si surface. Our goal is to experimentally investigate whether or not a nonpolymeric organic compound as contact to an inorganic semiconductor such as Si can provide the continuous control of the barrier height (BH). The barrier height Φ bp values of 0.51, 0.674, 0.75 and 0.79 eV for the Cu/pyronine-B/p-Si, Au/pyronine-B/p-Si, Al/pyronine-B/p-Si and Sn/pyronine-B/p-Si Schottky structures have obtained from the forward current–voltage (I–V) characteristics. It has been seen that the values of Φ bp are significantly larger than those of conventional Schottky diodes. © 2003 Elsevier B.V. All rights reserved. PACS: 73.40.Ei; 73. 30.+y; 73. 40.Ns; 61.82.Fk Keywords: Schottky barrier; Metal–interfacial layer–semiconductor contacts; Organic–inorganic semiconductor contact; Pyronine-B 1. Introduction It is well known that interface properties have a dom- inant influence on the device performance, reliability and stability [1–4]. The interface states and interfacial layer at the metal–semiconductor interface play an important role in the determination of the characteristic parameters of the de- vices [5–8]. The Schottky barrier height (SBH) is the dif- ference between the edge of the respective majority carrier band of the semiconductor and Fermi level at the interface. The SBHs of ideal, i.e. intimate, abrupt, homogeneous and defect-free Schottky contacts are determined by the contin- uum of metal-induced gap states (MIGS). Deviations from predicted by the MIGS model may be attributed to sec- ondary mechanisms like structure-related interface dipoles, interface structure and interface defects [5]. We can state more clearly that the surface-preparation methods serve ad- vantages over the normal wet cleaning, but they would not be ultimate solutions because successive Schottky metalliza- tion generally causes an interfacial modification. However, ∗ Corresponding author. Tel.: +90-442-231-4171; fax: +90-442-236-0948. E-mail address: aturut@atauni.edu.tr (A. Türüt). a passivation method can be designed to control the defec- tive states originated from the deposition of Schottky metal and interfacial reaction during metallization [2,5]. In general, the SBH Φ b is restricted to within the 0.4–0.70 eV range for p-Si independent of contact metal [1,2]. In spite of this, the formation of high-quality Schot- tky barrier diodes (SBDs) with a low ideality factor using thin interfacial films is one of the essential prerequisites for devices [1–3]. A primary technological challenge in the study of semiconductor interfaces has been the development of general routes to control the SBH [6]. For the barrier height (BH) enhancement or modification using the thin interfacial films, Hanselaer et al. [7] have found the barrier height values varied between 0.65 and 0.85 eV with value of n ranged between 1.5 and 3.0 for Ti/SiO x /p-Si diodes. Again, Hanselaer et al. [8] have studied the influence of pre-evaporation surface treatments on the electrical charac- teristics of p-Si/Au, Cr and Ti MIS diodes and they have ob- tained a value of 0.67 eV with an n value of 2.81 for p-Si/Au diodes and the barrier height values of 0.66 eV (n = 1.45) to 0.79 eV (n = 2.29) for p-Si/Cr diodes and the barrier height values of 0.58 eV (n = 2.26) to 0.75 eV (n = 1.76) for p-Si/Ti diodes. Horvath et al. [9] have reported 0.79 eV by forming a thin n-type layer near the Al/p-Si interface by 0379-6779/$ – see front matter © 2003 Elsevier B.V. All rights reserved. doi:10.1016/j.synthmet.2003.08.009