Determination of Contact Parameters of Au/n-Ge Schottky Barrier Diode with Rubrene Interlayer

Year 2017, Volume: 20 Issue: 1, 165 - 173, 01.03.2017

Murat Yıldırım

Abstract

Electrical characterization of an Au/n-Ge semiconductor Schottky diode with organic (rubrene) interface has been systematically carried out over a wide temperature range. In sample fabrication stage, first, the ohmic In contact has been performed on one surface of n-Ge wafer grown in direction of (100). Later, the other surface of the wafer has been coated with rubrene by spin-coating method and then the Schottky contact has been constituted on the organic material via thermal evaporation method. The current-voltage (I-V) characteristics of prepared Schottky diode has been measured at a temperature range of 150-300 K and it has been observed that the diode have a rather good rectification behavior at all temperature. By using the I-V characteristics, the idealite factor, barrier height and some other diode parameters have been calculated for all temperatures. These parameters have also been calculated by means of Cheung-Cheung method. Werner and Güttler’s model has been employed to analyze the temperature dependence of barrier height and ideality factor at low temperatures. The standard deviation of the zero-bias barrier height was calculated as 120 mV and the voltage coefficients of the barrier height were determined as 𝜌2 = 0.184 and 𝜌3 = 0.232 mV. At high temperatures, the zero-bias barrier height decreases with increasing temperature because of the temperature dependence of semiconductor band gap. The non-linearity has been observed in the Richardson plot due to temperature dependence of the zero-bias barrier height. Richardson constant was determined by using different methods. Of the current-voltage analysis’s has emerged an abnormal decrease of apparent barrier height and increase of ideality factor at low temperature. It is determined that these abnormalies result due to the barrier height inhomogeneities prevailing at the organic-semiconductor interface. As a result, homogeneities in Au/rubrene/n-Ge Schottky barrier diode can be successfully characterized by a Gaussian distribution.

Keywords

Schottky Contacts, Rubrene Thin Film, Gaussian Distribution, Inhomogeneities

References

• [1] Virkar, A. A., Mannsfeld, S., Bao, Z. and Stingelin, N. “Organic Semiconductor Growth and Morphology Considerations for Organic Thin‐Film Transistors”, Advanced Materials, 22: 3857-3875, (2010).
• [2] Schmechel, R. and von Seggern, H. “Electronic traps in organic transport layers”, Physica Status Solidi (a), 201: 1215-1235, (2004).
• [3] Mishra, A. and Bäuerle, P. “Small Molecule Organic Semiconductors on the Move: Promises for Future Solar Energy Technology”, Angewandte Chemie International Edition, 51: 2020-2067, (2012).
• [4] Djurovich, P. I., Mayo, E. I., Forrest, S. R. and Thompson M. E. “Measurement of the lowest unoccupied molecular orbital energies of molecular organic semiconductors”, Organic Electronics, 10: 515-520, (2009).
• [5] Wohlgenannt, M. “Organic magnetoresistance and spin diffusion in organic semiconductor thin film devices”, Physica Status Solidi RRL, 6: 229-242, (2012).
• [6] Huang, L.S. and Chen, C.H. “Recent progress on molecular organic electroluminescent materials and devices”, Materials Science and Engineering: R: Reports, 39: 143-222, (2002).
• [7] Chan, M.Y., Lai, S.L., Fung, M.K., Lee, C.S. and Lee, S.T. “Doping-induced efficiency enhancement in organic photovoltaic devices”, Applied Physics Letters, 90: 023504, (2007).
• [8] Karak, S., Lim, J. A., Ferdous, S., Duzhko, V. V. and Briseno, A. L. “Photovoltaic Effect at the Schottky Interface with Organic Single Crystal Rubrene”, Advanced Functional Materials, 24: 1039-1046, (2014).
• [9] Chen, Y. and Shih, I. “High mobility organic thin film transistors based on monocrystalline rubrene films grown by low pressure hot wall deposition”, Applied Physics Letters, 94: 083304, (2009).
• [10] Horowitz, G. “Organic Field-Effect Transistors”, Advanced Materials, 10: 365-377, (1998).
• [11] Dökme, İ. and Altındal, Ş. “On the intersecting behavior of experimental forward bias current-voltage (I-V) characteristics of Al/SiO2/p-Si (MIS) Schottky diodes at low temperatures”, Semiconductor Science and Technology, 21: 1053-1058, (2006).
• [12] Karataş, Ş., Altındal, Ş. and Çakar, M. Physica B, 357: 386-397, (2005).
• [13] Werner, J.H. and Guttler, H.H. “Temperature dependence of Schottky barrier heights on silicon”, Journal of Applied Physics, 73: 1315-1319, (1993).
• [14] Cimili, F.E., Sağlam, M., Efeoğlu, H. and Türüt, A. “Temperature-dependentcurrent–voltage characteristics of the Au/n-InP diodes with inhomogeneous Schottky barrier height”, Physica B, 404: 1558-1562, (2009).
• [15] Yüksel, Ö. F. “Temperature dependence of current–voltage characteristics of Al/p-Si (100) Schottky barrier diodes”, Physica B, 404: 1993-1997, (2009).
• [16] Wu, J. R., Wu, Y.H., Hou, C.Y., Wu, M.L., Lin, C.C. and Chen, L.L. “Impact of fluorine treatment on Fermi level depinning for metal/germanium Schottky junctions”, Applied Physics Letters, 99: 253504, (2011).
• [17] Janardhanam, V., Yun, H.J., Lee, J., Reddy, V. R., Hong, H., Ahn, K.S. and Choi, C.J. “Depinning of the Fermi level at the Ge Schottky interface through Se treatment”, Scripta Materialia, 69: 809-811, (2013).
• [18] Khurelbaatar, Z., Kang, M., Shim, K., Yun, H., Lee, J., Hong, H., Chang, S., Lee, S. and Choi C. “Temperature dependent current–voltage characteristics of Au/n-type Ge Schottky barrier diodes with graphene interlayer”, Journal of Alloys and Compounds, 650: 658-663, (2015).
• [19] Lieten, R. R., Degroote, S., Kuijk, M. and Borghs G. “Ohmic contact formation on n-type Ge”, Applied Physics Letters, 92: 022106, (2008).
• [20] Şimşir, N., Şafak, H., Yüksel, Ö.F. and Kuş, M. “Investigation of current–voltage and capacitance–voltage characteristics of Ag/perylene-monoimide/n-GaAs Schottky diode”, Current Applied Physics, 12: 1510-1514, (2012).
• [21] Chand S. and Kumar, J. “Current-voltage characteristics and barrier parameters of Pd2Si/p-Si(111) Schottky diodes in a wide temperature range”, Semiconductor Science and Technology, 10: 1680-1688, (1995).
• [22] Rhoderick, E. H. “Metal-Semiconductor Contacts”, Clarendon, Oxford, UK, (1978).
• [23] Sze, S.M. “Physics of Semiconductor Devices”, John Wiley and Sons, New York, USA, (1981).
• [24] Zhiqiang, L., Xia, A., Quanxin, Y., Meng, L., Xing, Z. and Ru, H. “Tuning Schottky Barrier Height in Metal/n-Type Germanium by Inserting an Ultrathin Yttrium Oxide Film”, ECS Solid State Letters, 1: Q33-Q34, (2012).
• [25] Khurelbaatar, Z., Kil, Y., Yun, H., Shim, K., Kim, K., Lee, S., Choi, C. and Nam, J. T. “Modification of Schottky barrier properties of Au/n-type Ge Schottky barrier diode using monolayer graphene interlayer”, Journal of Alloys and Compounds, 614: 323-329, (2014).
• [26] Güzeldir B., Sağlam, M., Ateş, A. and Türüt, A. “Determination of the some electronic parameters of nanostructure copper selenide and Cu/Cu3Se2/n-GaAs/In structure”, Journal of Alloys and Compounds, 627: 200-205, (2015)
• [27] Werner, J.H. and Güttler, H.H. “Barrier inhomogeneities at Schottky contacts”, Journal of Applied Physics, 69: 1522-1533, (1991).
• [28] Kumar, A., Vinayak, S. and Singh, R. “Micro-structural and temperature dependent electrical characterization of Ni/GaN Schottky barrier diodes”, Current Applied Physics, 13: 1137-1142, (2013).
• [29] Kalinina, E.V., Kuznetsov, N.I., Dmitriev, V.A., Irvine, K.G. and Carter, C.H. J. “Schottky barriers on n-GaN grown on sic”, Journal of Electronic Materials, 25: 831-834, (1996).
• [30] Vural, Ö., Şafak, Y., Altındal, Ş. and Türüt, A. “Current–voltage characteristics of Al/Rhodamine-101/n-GaAs structures in the wide temperature range”, Current Applied Physics, 10: 761-765, (2010).
• [31] Yüksel, Ö.F., Tuğluoğlu, N., Şafak, H., Nalçacıgil, Z. and Karadeniz, S. “Analysis of temperature dependent electrical properties of Au/perylene-diimide/n-Si Schottky diodes”, Thin Solid Films, 534: 614-620, (2013).
• [32] Bengi, A., Altındal, Ş., Özçelik, S., Agaliyeva, S.T. and Mammadov, T.S. “Analysis of temperature dependent electrical characteristics of Au/n-GaAs/GaAs structures in a wide temperature range”, Vacuum, 83: 276-281, (2009).
• [33] Altuntaş, H., Altındal, Ş., Özçelik, S. and Shtrikman, H. “Electrical characteristics of Au/n-GaAs Schottky barrier diodes with and without SiO2 insulator layer at room temperature”, Vacuum, 83: 1060-1065, (2009).
• [34] Yüksel, Ö.F., Kuş, M., Şimşir, N., Şafak, H., Şahin, M. and Yenel, E. “A detailed analysis of current-voltage characteristics of Au/perylene-monoimide/n-Si Schottky barrier diodes over a wide temperature range”, Journal of Applied Physics, 110: 024507, (2011).
• [35] Barış, B., Yüksel, Ö.F., Tuğluoğlu, N. and Karadeniz, S. “Double barrier heights in 5, 6, 11, 12-tetraphenylnaphthacene (rubrene) based organic Schottky diode”, Synthetic Metals, 180: 38-42, (2013).
• [36] Güllü, Ö., Aydoğan, Ş. and Türüt, A. “Electronic parameters of high barrier Au/Rhodamine-101/n-InP Schottky diode with organic ınterlayer”, Thin Solid Films, 520: 1944-1948, (2012).
• [37] Soylu, M., Abay, B. and Onganer, Y. “Electrical characteristics of Au/Pyronine-B/moderately doped n-type InP Schottky structures in a wide temperature range” Journal of Alloys and Compounds, 509: 5105-5111, (2011).
• [38] Tuğluoğlu, N., Karadeniz, S. and Altındal, Ş. “Effect of series resistance on the performance of silicon Schottky diode in the presence of tin oxide layer”, Applied Surface Science, 239: 481-489, (2005).
• [39] Şahin, M., Şafak, H., Tuğluoğlu, N. and Karadeniz, S. “Temperature-dependent of current-voltage characteristics of Ag/p-SnS Schottky barrier diodes”, Applied Surface Science, 242: 412-418, (2005).
• [40] Karadeniz, S., Tuğluoğlu, N., Şahin, M. and Şafak, H. “Series resistance calculation for Ag contacts on single crystal layered p-SnS and p-SnSe compound semiconductors in the wide temperature range”, Microelectronic Engineering, 81: 125-131, (2005).
• [41] Tuğluoğlu, N., Yakuphanoğlu, F. and Karadeniz, S. “Determination of the interface state density of the In/p-Si Schottky diode by conductance and capacitance–frequency characteristics”, Physica B: Condensed Matter, 393: 56-60, (2007).
• [42] Cheung, S.K. and Cheung, N.W. “Extraction of Schottky diode parameters from forward current‐voltage characteristics”, Applied Physics Letters, 49: 85–87, (1986).
• [43] Chawanda, A., Mtangi, W., Auret, F. D., Nel, J., Nyamhere, C. and Diale M. “Current–voltage temperature characteristics of Au/n-Ge (1 0 0) Schottky diodes”, Physica B: Condensed Matter, 407: 1574-1577, (2012).
• [44] Murakami, H., Fujioka, T., Ohta, A., Bando, T., Higashi, S. and Miyazaki S. “Characterization of interfaces between chemically cleaned or thermally oxidized germanium and metals”, ECS Transactions, 33: 253-262, (2010).
• [45] Güttler, H.H. and Werner, J.H. “Influence of barrier inhomogeneities on noise at Schottky contacts”, Applied Physics Letters, 56: 1113-1115, (1990).
• [46] Chand, S. and Kumar, J. “On the existence of a distribution of barrier heights in Pd2Si/Si Schottky diodes”, Journal of Applied Physics, 80: 288-294, (1996).
• [47] Chand, S. and Kumar J., “Current transport in Pd2Si/n-Si(100) Schottky barrier diodes at low temperatures”, Applied Physics A, 63: 171-178, (1996).
• [48] Gümüş, A., Türüt, A. and Yalçın, N. “Temperature dependent barrier characteristics of CrNiCo alloy Schottky contacts on n-type molecular-beam epitaxy GaAs”, Journal of Applied Physics, 91: 245-250, (2002).
• [49] Yıldırım, N., Ejderha, K., and Türüt, A. “On temperature-dependent experimental I - V and C - V data of Ni / n -GaN Schottky contacts”, Journal of Applied Physics, 108: 114506, (2010).
• [50] Schmitsdorf, R.F., Kampen, T.U. and Mönch, W. “Correlation between barrier height and interface structure of AgSi (111) Schottky diodes”, Surface Science, 324: 249-256, (1995).
• [51] Mönch, W. “Barrier heights of real Schottky contacts explained by metal-induced gap states and lateral inhomogeneities”, Journal of Vacuum Science & Technology B, 17: 1867-1876, (1999).
• [52] Farag, A.A.M. and Yahia, I.S. “Rectification and barrier height inhomogeneous in Rhodamine B based organic Schottky diode”, Synthetic Metals, 161: 32-39, (2011).
• [53] Chand, S. and Kumar, J. “Effects of barrier height distribution on the behavior of a Schottky diode”, Journal of Applied Physics, 82: 5005-5010, (1997).
• [54] Yüksel, Ö.F., Tuğluoğlu, N., Gülveren, B., Şafak, H. and Kuş, M. “Electrical properties of Au/perylene-monoimide/p-Si Schottky diode”, Journal of Alloys and Compounds, 577: 30-36, (2013).
• [55] Song, Y.P., Van Meirhaeghe, R.L., Laflere, W.F. and Cardon, F. “On the difference in apparent barrier height as obtained from capacitance-voltage and current-voltage-temperature measurements on Al/p-InP Schottky barriers”, Solid State Electronics, 29: 633-638, (1986).
• [56] Çaldıran, Z., Aydoğan, Ş., Yeşildağ, A., Ekinci, D., Kurudirek, S.V. and Türüt A. “Temperature-dependent current–voltage measurements of Au/C9H7N/p-Si: Characterization of a metal–organic-semiconductor device”, Materials Science in Semiconductor Processing, 34: 58-64, (2015).