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- MakaleAçık Erişim2021Scopus SJRQ13D-graphene-laser patterned p-type silicon Schottky diode
Orhan, Elif Oz; Efil, Esra; Bayram, Ozkan; Kaymak, Nuriye; Berberoğlu, Halil; Candemir, Ozun; Pavlov, Ihor; Ocak, Sema Bilge
The influence of the laser patterning (LP) process on the quality of graphene (Gr) film and Schottky diode characteristics was researched in this study. First of all, p-type silicon (Si) was patterned by homemade femtosecond laser source. To compare the resulting effect, non-patterned n-Si and p-Si were used as substrates. To achieve vertically oriented three-dimensional (3D) Gr nanosheets (VGNs) onto the laser patterned p-type Si, non-patterned n-Si, and p-Si substrates, we used Radio-Frequency Plasma Enhanced Chemical Vapor Deposition (RF-PECVD) technique. Then, Raman analyses for VGNs obtained on patterned and non-patterned p-Si and n-Si substrates were conducted. All results indicate that the Gr obtained on all substrates is vertically oriented. Scanning electron microscopy (SEM) analyses were also performed to obtain information about the morphological properties of the 3D Gr structure. In addition, the influence of the laser patterning at the Gr-Si interface was evaluated by comparing two sets of devices which are junctions of Gr-Laser Patterned Si (Gr-LPSi) and Gr-Insulator-Silicon (Gr-I-Si) at 300 K in the dark medium. D1 device consists of a Gr-LPSi junction that involves RF-PECVD grown Gr on the silicon, whose surface exposed the laser beam for patterning. D2 device consists of a Gr-I-Si junction that involves RF-PECVD grown Gr onto the silicon, whose surface involves a thin native oxide layer (~2 nm). The results show that the laser treatment causes an increment in Schottky barrier height (SBH) and decreases leakage currents under a reverse bias voltage of the diode. Notably, we have seen the influence of the laser patterning process on 3D Gr nano-sheets which is that the entire surface of the substrate has now reformed new structures in the nano-sphere and nano-rose morphology, so we believe that this is the first work that shows these structures in this form.
AtıfScopus14WoS13OpenAlex13
İncele - MakaleYalnız künye2021Scopus SJRQ2Double-exponential current-voltage (I-V) behavior of bilayer graphene-based Schottky diode
Kutluoǧlu, Esra Efil; Orhan, Elif Oz; Tataroǧlu, Adem; Bayram, Ozkan
Researches on layered materials such as graphene have attracted lots of attention recently. It has been shown that these materials have make a junction with many semiconductor materials that behave like Schottky diodes and have rectifying characteristics. The comprehension of its fabrication process and properties are a critical need toward graphene-based integrated electronics. The purpose of this study is to find out the current-voltage (I-V) performance of Bilayer Graphene (BLGr) based heterostructure fabricated on Al2O3/p-Si, and the effect of BLGr on diode parameters. Graphene has been grown on copper (Cu) foil by Chemical Vapor Deposition (CVD) method and transferred onto Al2O3/p-Si by using the polymethyl methacrylate (PMMA) wet transfer method. Raman analysis has been performed to obtain supportive information about CVD synthesized graphene film. The I-V plot of the diode exhibited two linear regions named Region 1 (0.08-0.19 V) and Region 2 (0.21-0.40 V). The double-exponential I-V behavior of the diode has been analyzed. The diode characteristics such as barrier height (ΦB0), series resistance (Rs), and ideality factor (n) have been calculated by using thermionic emission (TE), Norde, and Cheung methods. Especially, the values of the barrier height were compared with one another. It was found that they are in good agreement. Additionally, current conduction mechanisms of the diode were investigated using the forward bias ln(I) versus ln (V) plot. At lower and higher forward bias regions, the conduction mechanisms were determined as ohmic behavior and trap charge limiting current mechanism (TCLC), respectively.
AtıfScopus3WoS3OpenAlex4İncele