Surface-barrier Structures Au/n-CdS: Fabrication and Electrophysical Properties

Authors R. Petrus1 , H. Ilchuk1 , A. Kashuba1,2, I. Semkiv1 , E. Zmiiovska1 , F. Honchar1, R. Lys2

1Lviv Polytechnic National University, General Physics Department, 12, S. Bandera St., 79013 Lviv, Ukraine

2Ivan Franko National University of Lviv, Faculty of Electronics and Computer Technologies, 107, Tarnavsky St., 79005 Lviv, Ukraine

Issue Volume 11, Year 2019, Number 3
Dates Received 21 February 2019; revised manuscript received 0 June 2019; published online 25 June 2019
Citation R. Petrus, H. Ilchuk, A. Kashuba, et al., J. Nano- Electron. Phys. 11 No 3, 03020 (2019)
PACS Number(s) 73.30. + y, 73.63. – b, 73.40.Ei
Keywords Magnetron sputtering (14) , Thin films (60) , CdS (33) , Schottky barrier (8) , Photoconductivity (3) .

The results of the electrophysical properties study of Au/n-CdS surface-barrier structures (SBS) obtained by radio frequency (RF) magnetron sputtering are presented. It was established that CdS films crystallize in the space group P63mc. The results of I-V characteristics investigation for films in the dark and under illumination are presented. The ideality factor, the potential barrier height on the metal contact, the saturation current, the resistivity, the rectification factor and the built-in potential of the structure in the dark and under illumination are calculated based on the behavior of the I-V characteristic.In the process of illumination by a solar radiation simulator of the structure from the side of Au, the rectification factor k increases from 3 to 22 in comparison with the dark I-V characteristic. The multistage tunneling and recombination processes with the involvement of the surface states at the metallurgical Au/n-CdS interface is a dominant mechanism of charge transfer which established from the dark I-V characteristics of the forward-bias voltages. For the illuminated I-V characteristics, for biases  0.6 V the tunneling and recombination mechanisms of the charge transport are dominant, and for biases  0.6 V, the contribution of the tunneling mechanism increases. At reverse voltages for the dark and illuminated I-V characteristics, for biases  0.3 V the dominant mechanism of charge transport is tunneling of charge carriers or currents confined by the space charge in the saturation mode of the carrier rate, and for biases  0.3 V – currents confined by the space charge in the mobility mode.From the photoconductivity (PC) investigation, the band gap and absorption dependencies of the fabricated film were established.

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