Materials Science and Engineering B 193 (2015) 61–69 Contents lists available at ScienceDirect Materials Science and Engineering B jo ur nal ho me page: www.elsevier.com/locate/mseb The comparison of electrical characteristics of Au/n-InP/In and Au/In 2 S 3 /n-InP/In junctions at room temperature T. C ¸ akıcı, M. Sa˘ glam ∗ , B. Güzeldir Department of Physics, Faculty of Sciences, University of Atatürk, 25240 Erzurum, Turkey a r t i c l e i n f o Article history: Received 29 May 2014 Received in revised form 25 October 2014 Accepted 5 November 2014 Available online 21 November 2014 Keywords: Spray pyrolysis Electrical properties In2S3 Schottky diode Series resistance a b s t r a c t We fabricated Au/n-InP/In and Au/In 2 S 3 /n-InP/In junctions and investigated their electrical properties at room temperature. The In 2 S 3 thin ﬁlm has been directly formed on n-type InP substrate with spray pyrolysis method at 200 ◦ C substrate temperature. Detailed structural and optical properties of the ﬁlm have been investigated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and absorption techniques. The band gap energy of In 2 S 3 by using spectral data of absorption has been deter- mined to be about 2.80 eV. The values of the ideality factor and barrier height of the Au/n-InP/In and Au/In 2 S 3 /n-InP/In junctions have been found as n = 1.01, ˚ b = 0.469 eV and n = 1.07, ˚ b = 0.543 eV, respec- tively. Likewise, the values of barrier height and series resistance of both samples have been obtained from Norde method and they have been calculated as 0.456 eV, 59.081  for Au/n-InP/In junction and 0.518 eV, 101.302  for Au/In 2 S 3 /n-InP/In junction, respectively. © 2014 Elsevier B.V. All rights reserved. 1. Introduction The Schottky diode is a rectifying metal–semiconductor contact formed between a metal and an n-doped or p-doped semi- conductor. Since the Schottky diode is formed by the contact between the metal and semiconductor, the metal–semiconductor interface quality has a signiﬁcant inﬂuence on the electri- cal characteristics of Schottky diodes. The Schottky barrier inhomogeneity in metal–semiconductor contacts is of great tech- nological importance and has been a long-standing topic of research [1,2]. It is well known that the interfacial proper- ties of metal–semiconductor contacts have a dominant inﬂuence on the device performance, reliability, and stability. There is always native thin insulating layer of oxide on the surface of the semiconductor in most practical metal–semiconductor contacts. However, thin ﬁlm interfacial layer between metal and inorganic semiconductor can be constructed by many methods. This ﬁlm modiﬁes some electrical characteristics of the diodes [3]. The per- formance of these structures especially depends on the formation of interfacial thin layer between metal and semiconductor, the inter- face states located at the semiconductor/insulator interface, series resistance and an inhomogeneous Schottky barrier contacts. There are currently a vast number of reports of experimental studies on Schottky barrier height in a great variety of metal–interfacial thin ∗ Corresponding author. Tel.: +90 4422314176. E-mail address: msaglam@atauni.edu.tr (M. Sa˘ glam). layer–inorganic semiconductor structures [4–13]. Group III–V com- pound semiconductors, particularly indium phosphide (InP), are promising materials for high-speed electrical and optoelectronic devices. This is due to the superior characteristics of InP, such as the large direct band gap and high electron mobility, substrate velocity, and breakdown voltage, which are very important param- eters in electronic devices [12,14]. The potential barrier height of Schottky junctions based on InP is usually smaller than 0.5 eV and but rarely higher values are also available [15–17]. The several attempts have been made in order to modify and control the bar- rier height by using thin ﬁlm layer at InP metal–semiconductor junctions. This layer converts a metal–semiconductor structure into a metal–interfacial thin ﬁlm layer–inorganic semiconductor structures. Up to now, various chemical synthesis methods have been used in preparation of In 2 S 3 thin ﬁlm. However, in the litera- ture there has been no report on preparation of Au/In 2 S 3 /n-InP/In junction by means of spray pyrolysis method. Spray pyrolysis is a chemical method, which is relatively simple, reproducible, size controllable, low cost and continuous for synthesis of some thin ﬁlm. In our previous study, we investigated the effects of ther- mal annealing on the electrical characteristics of Au/n-InP/In diode [18]. In this work, Au/n-InP/In and Au/In 2 S 3 /n-InP/In junctions have been fabricated by spray pyrolysis method and the effects of the In 2 S 3 interlayer on conventional metal–semiconductor contacts have been inquired in terms of electrical properties of the junctions. Therefore, it is aimed to investigate the suitability and possibility of the In 2 S 3 thin ﬁlm for use in barrier modiﬁcation of metal–n type InP semiconductor devices. http://dx.doi.org/10.1016/j.mseb.2014.11.003 0921-5107/© 2014 Elsevier B.V. All rights reserved.