Study of System Pressure Dependence on n-TiO2/p-Si Hetrostructure for Photovoltaic Applications

Document Type : Research Paper


Department of physic, Roudehen Branch,Islamic Azad university , Roudehen, Iran



This study reports the fabrication of n-TiO2/p-Si hetrojunction by deposition of TiO2nanowires on p-Si substrate. The effect of system pressure and the current-voltage (I-V) characteristics of n-TiO2/p-si hetrojunction were studied. The morphology of the samples was investigated by Field Emission Scanning Electron Microscopy (FESEM) which confirms formation of TiO2 nanowires that their diameters increase with increasing the pressure of system. The I-V characteristics were measured to investigate the hetrojunction effects of under forward and reverse biases at different system pressure by sweeping in the voltage from 0 to +6 V, then to -6 V, and finally reaching 0 V. TiO2/Si diodes   in the system pressure 60 mbar and 30 mbar indicated that a p-n junction formed in the n-TiO2/p-Si hetrojunction. But as the system pressure increased to 1000 mbar, the I-V characteristics became inversed. This treatment can be scribed by the change of the energy band structure of TiO2.


[1]. A. Rothschild, A. Evakov, Y. Shapira, N. Ashkenasy and Y. Komen, Surrf. Sci. 419(2003) 532-537.
 [2]. E. G. J, Wijnhoven and W.L. Vos, Science 281 (1998) 802-807.
[3]. A.Richel, N.P. Johnson and D. McComb. Appl.phys. Lett. 76 (2000) 1816-1822.
[4]. S. P. Albu, A. Ghicov, J. M. Macak, R. Hahn and P. Schmuki, NanoLett. 7 (2007) 862-870.
[5]. A.r. Armstrong, G. Armstrong, J.Canales, R. Garcia and P.G. Bruce. Adv. Mater. 17 (2005) 862-868.
[6]. G. Armstrong, A.r. Armstrong, J.Canales, R. Garcia and P.G. Bruce. 9 A (2006) 139-145.
[7]. N.G. Park, J. Van de Lagemaat and A. J. Frank, J. Phys. Chem. B. 104 (2000) 8989-8994.
[8]. G. de Cesare, F. Galluzzi, F. Irrera, D. Lauta, F. Ferrazza, M.Tucci, J. Non Cryst. Solids 198 (1996) 1189-1195.
[9]. K. Y. Dong and Y. K. Dong. Nano Lett. 3 (2003) 207-212.
[10] G. H. Du, Q. Chen, R. C. Che, Z.Y. Yuan and L. M. Peng. Appl. Phys. Lett. 79 (2001) 3702-3707.
[11]. L. Miao, S. Tanemura, S. Toh, K. Kaneko and M. J. Cryst. Growth 264 (2004) 246-252.
[12]. J-M.Wu, H. Shin, W-T. Wu, Y-K. Tseng,I-Ch. Chen, J. Cryst. Growth 281 (2005) 384-389.
[13]. J-M. Wu,  W-T. Wu, H. Shin, J. Electrochem. Soc. 152 G (2005) 613-618.
[14]. J. Wu, H. Shin, W. Wu, J. Vac. Sci. Technol. B 23 (2005) 2122-2129.
[15]. K. Keis, A. Roos, J. Opt. Mater 20 (2002) 35
[16]. C. S. Rout, G. U. Kulkarni, C. N. R. Rao, J. Phys. D: Appl. Phys. 48 (2007) 2777-2784.
[17]. S.Ramezani Sani. A. Morteza Alli. R.Jafari. J.Physica B. 406 (2011) 3383-3390.
[18]. DH. Wang. L.Jia, XL. Wu, LQ. Lu, Aw, Xu, Nanoscle 4 (2012) 576-582