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Field emission graphene–oxide–silicon field effect based photodetector
Author(s) -
Srisonphan Siwapon,
Kanokbannakorn Weerawoot,
Teerakawanich Nithiphat
Publication year - 2015
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201510199
Subject(s) - quantum efficiency , optoelectronics , materials science , heterojunction , impact ionization , silicon , photodetector , graphene , nanotechnology , physics , ionization , ion , quantum mechanics
Silicon‐based devices keep moving into smaller dimension for improving the speed, efficiency, and low‐power consumption. Novel designed semiconductor device architectures are needed to overcome the physical limitations. An integration of well‐designed nanostructure and nanomaterials can potentially establish new principles and approaches to nanoelectronic and photonic devices. We herein demonstrate a graphene/SiO 2 /p‐Si (GOS) heterostructure with an embedded nanoscale mesa, forming a GOS‐Mesa field‐effect photodetector. The proposed structure exhibits that multiple exciton generation (MEG) can occur in a quantum‐confined two‐dimensional electron gas (2DEG) region via impact ionization, leading to high internal quantum efficiency ( η IQE ). The numerical simulation of the carrier multiplication (CM) factor in our designed structure finds a reasonable agreement with empirical data. Simulated and measured internal quantum efficiency demonstrate ∼195% and ∼135% of UV–Vis radiation, respectively. A vertically confined 2DEG plays an important role not only in enabling the electron emission process which is responsible for the flowing of electron current, but also in developing a highly localized electric field (up to ∼10 6 V/cm) at the SiO 2 /Si interface, enabling an impact ionization process under photon energy of merely ∼1.95 eV. Our findings demonstrate that carrier multiplication can be achieved in a suitably designed nanoscale structure in conjunction with nanomaterial on silicon‐based devices, providing incentive to better understand MEG within quantum wells in 2DEG systems, and being a research path to enhancing the efficiency of future solar harvesting technologies. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)