Photoresponse characteristics of Au/(CoFe2O4-PVP)/n-Si/Au (MPS) diode

• Published in: Journal of materials science. Materials in electronics Vol. 32; no. 12; pp. 15732 - 15739
• Main Authors: Ulusan, A. Buyukbas, Tataroglu, A., Altındal, Ş., Azizian-Kalandaragh, Y.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2021; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Cobalt ferrites; Dark current; Dielectric properties; Diodes; Electric fields; Energy; Illumination; Materials Science; Optical and Electronic Materials; Parameters; Photoelectric effect; Photoelectric emission; Photosensitivity; Polymers; Polyvinyl alcohol; Thermionic emission
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-021-06124-w

Photoresponse characteristics of the Au/(CoFe 2 O 4 -PVP)/n-Si (MPS) diode were investigated using current–voltage ( I – V ) measurements achieved under dark and various illumination conditions. The experimental results showed that the MPS diode has a good response to the illumination. Especially, in reverse bias region, photocurrent ( I ph ) increases with increasing illumination intensity ( P ) due to the formation of electron–hole pairs. The double-logarithmic I ph - P plot has a good relation with 1.27 slope and such high value of slope indicates a lower density of the unoccupied trap level. This indicates that the diode exhibits a good photoconductive and photovoltaic behavior. The photo-to-dark current ratio confirms the photosensitivity of the diode. Thermionic emission (TE) theory was used to determine the diode electronic parameters such as saturation current ( I 0 ), ideality factor ( n ) and barrier height (Φ B0 ) and their values were calculated from the measured I – V data. Moreover, the Φ B0 and series resistance ( R s ) were extracted from an alternative method suggested by Norde. All these parameters (Φ B0 , n , R s , and I 0 ) decrease with increasing illumination intensity and there is a good linear correlation between Φ B0 and n as Φ B0 ( n ) = 4.72 × 10 −2 n  + 0.5464 eV. As a result, the fabricated MPS diode due to the excellent photoresponse can be used for photovoltaic applications.