Vol.:(0123456789) 1 3 J Mater Sci: Mater Electron DOI 10.1007/s10854-016-6326-z Investigation of photo-induced efect on electrical properties of Au/PPy/n-Si (MPS) type schottky barrier diodes Gülçin Ersöz 1,2  · İbrahim Yücedağ 1  · Sümeyye Bayrakdar 1  · Şemsettin Altındal 3  · Ahmet Gümüş 4   Received: 16 September 2016 / Accepted: 30 December 2016 © Springer Science+Business Media New York 2017 conditions, barrier inequality, the thickness of PPy inter- layer and its roughness. The open-circuit voltage of the photodiode was found as 0.36 V under 100 W/m 2 illumi- nation level. This is evidence that the fabricated sample is very sensitive to illumination. Therefore, it can be put into practice in optoelectronic industries as a photodiode or solar cells. 1 Introduction Although there have been many studies on the organic based inorganic semiconductors devices as function of fre- quency in recent years, applied bias voltage, temperature, illumination intensity, and radiation [1–16], but their cur- rent conduction mechanisms (CCMs) have not been illu- minated enough yet. The CCMs are dependent on some quantities such as the creation of barrier height (Ф B ) and interfacial layer which is between metal and semiconduc- tor, homogeneity, applied voltage, series resistance (R s ) and shunt resistance (R sh ), the concentration of doping atoms (donor or acceptor), temperature of the samples, sur- face states (N ss ), frequency, polarization and illumination or radiation [17–22]. Among them, especially the inter- facial layer, R s , N ss and illumination are more efective on the electrical behaviors of these devices. In addition, the dielectric constant of the used of interfacial layer is very important [23–25]. Usually, conventional SiO 2 and SnO 2 are used an interfacial layer, but both the formation of these material is expensive and they have low dielectric constant. Using an organic thin flm on the semiconductor as inter- facial layer can be modifed the electrical and dielectric characteristics of metal-semiconductor (MS) type SBDs by Campell et al. [26]. They showed that the active barrier height may be either raised or reduced by using an organic Abstract Au/PPy/n-Si (MPS) type Schottky barrier diodes (SBDs) were produced and their current–voltage (I–V) characteristics were measured in the positive and negative bias regions at 300 K. The basic electronic quan- tities such as reverse-saturation current (I o ), ideality factor (n), zero-bias barrier height (Ф B0 ), series (R s ) and shunt resistances (R sh ) were obtained by using I–V data in total darkness and illumination (100 W/m 2 ). The values of these parameters were found as 7.79 × 10 −9  A, 5.41, 0.75 eV, 1 kΩ and 130 MΩ in dark) and 4 × 10 −9  A, 4.89, 0.77 eV, 0.9 kΩ and 1.02 MΩ under illumination), respectively. Also the energy density distribution behaviors of surface states (N ss ) have been acquired by calculation of efective barrier height (Ф e ) and ideality factor n (V) depending on voltage in total darkness and illumination. The values of N ss show an exponentially increase from the mid-gap of Si to the lower part of conduction band (E c ) for two con- ditions. The possible current conduction mechanisms were determined by plotting of the double logarithmic I–V plots in the positive voltage zone and the value of current was found proportional to voltage (I∼V m ). The high values of n and R s were ascribed to the certain density distribution of N ss localized at semiconductor/PPy interface, surface * Gülçin Ersöz glcnersoz@gmail.com 1 Department of Computer Engineering, Technology Faculty, Düzce University, 81620 Düzce, Turkey 2 Department of Computer Programming, Rumeli Vocational High School, Rumeli University, 34570 Istanbul, Turkey 3 Department of Physics, Faculty of Sciences, Gazi University, 06500 Ankara, Turkey 4 Department of Physics, Faculty of Arts and Sciences, Niğde University, 51000 Niğde, Turkey