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Tunable Schottky barrier and high responsivity in graphene/Si-nanotip optoelectronic device
- Source :
- 2D Materials 4 (2017) 015024
- Publication Year :
- 2016
-
Abstract
- We demonstrate tunable Schottky barrier height and record photo-responsivity in a new-concept device made of a single-layer CVD graphene transferred onto a matrix of nanotips patterned on n-type Si wafer. The original layout, where nano-sized graphene/Si heterojunctions alternate to graphene areas exposed to the electric field of the Si substrate, which acts both as diode cathode and transistor gate, results in a two-terminal barristor with single-bias control of the Schottky barrier. The nanotip patterning favors light absorption, and the enhancement of the electric field at the tip apex improves photo-charge separation and enables internal gain by impact ionization. These features render the device a photodetector with responsivity (3 A/W for white LED light at 3 mW/cm2 intensity) almost an order of magnitude higher than commercial photodiodes. We extensively characterize the voltage and the temperature dependence of the device parameters and prove that the multi-junction approach does not add extra-inhomogeneity to the Schottky barrier height distribution. This work represents a significant advance in the realization of graphene/Si Schottky devices for optoelectronic applications.<br />Comment: Research paper, 22 pages, 7 figures
- Subjects :
- Condensed Matter - Mesoscale and Nanoscale Physics
Subjects
Details
- Database :
- arXiv
- Journal :
- 2D Materials 4 (2017) 015024
- Publication Type :
- Report
- Accession number :
- edsarx.1607.06584
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1088/2053-1583/4/1/015024