Browsing by Author "Fidan, M."

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Citation - WoS: 5
Citation - Scopus: 4
Graphene/SOI-based self-powered Schottky barrier photodiode array
(AIP Publishing, 2022) A. Yanilmaz; M. Fidan; O. Unverdi; C. Celebi; Fidan, M.; Çelebi, C.; Yanilmaz, A.; Unverdi, O.
We have fabricated a four-element graphene/silicon on insulator (SOI) based Schottky barrier photodiode array (PDA) and investigated its optoelectronic device performance. In our device design monolayer graphene is utilized as a common electrode on a lithographically defined linear array of n-type Si channels on a SOI substrate. As revealed by wavelength resolved photocurrent spectroscopy measurements each element in the PDA structure exhibited a maximum spectral responsivity of around 0.1 A/W under a self-powered operational mode. Time-dependent photocurrent spectroscopy measurements showed excellent photocurrent reversibility of the device with ~1.36 and ~1.27 mu s rise time and fall time respectively. Each element in the array displayed an average specific detectivity of around 1.3 x 10(12) Jones and a substantially small noise equivalent power of ~0.14 pW/Hz(-1/2). The study presented here is expected to offer exciting opportunities in terms of high value-added graphene/Si based PDA device applications such as multi-wavelength light measurement level metering high-speed photometry and position/motion detection.
Citation - WoS: 4
Citation - Scopus: 4
Light-induced modification of the Schottky barrier height in graphene/Si based near-infrared photodiodes
(ELSEVIER, 2022) M. Fidan; G. Donmez; A. Yanilmaz; O. Unverdi; C. Celebi; Donmez, G.; Fidan, M.; Celebi, C.; Yanilmaz, A.; Unverdi, O.
The impact of light on the Schottky barrier height (SBH) in p-type graphene/n-type Si (p-Gr/n-Si) based nearinfrared photodiodes is investigated. Hall effect and optoelectronic transport measurements carried out under illumination of 905 nm wavelength light showed that zero-bias SBH in such photodiodes can be effectively tuned in a range between 0.7 and 0.9 eV consistent with the variation in their open-circuit voltage. Shockley-Read-Hall model which considers the charge recombination through mid-gap and interface states at the p-Gr/n-Si heterojunction is used to explain the experimentally observed nonlinear dependence of SBH on the incident light. Light induced tunability of SBH at the graphene/semiconductor heterojunction is of great importance especially for the development of new generation optically driven devices in which graphene acts as a functioning element.