High performance, self-powered photodetectors based on a graphene/silicon Schottky junction diode

Dharmaraj Periyanagounder, Paulraj Gnanasekar, Purushothaman Varadhan, Jr-Hau He, Jeganathan Kulandaivel

Research output: Contribution to journalArticlepeer-review

124 Scopus citations


Electron-hole pair separation and photocurrent conversion at two-dimensional (2D) and three-dimensional (3D) hybrid interfaces are important for achieving high performance, self-powered optoelectronic devices such as photodetectors. In this regard, herein, we designed and demonstrated a graphene/silicon (Gr/Si) (2D/3D) van der Waals (vdW) heterostructure for high-performance photodetectors, where graphene acts as an efficient carrier collector and Si as a photon absorption layer. The Gr/Si heterojunction exhibits superior Schottky diode characteristics with a barrier height of 0.76 eV and shows good performance as a self-powered detector, responding to 532 nm at zero bias. The self-powered photodetector functions under the mechanism of photovoltaic effect and exhibits responsivity as high as 510 mA W with a photo switching ratio of 10 and a response time of 130 μs. The high-performance vdW heterostructure photodetector demonstrated herein is attributed to the Schottky barrier that effectively prolongs the lifetime of photo-excited carriers, resulting in fast separation and transport of photoexcited carriers. The self-powered photodetector with superior light harvesting and carrier transport behaviour is expected to open a window for the technological implementation of Si-based monolithic optoelectronic devices.
Original languageEnglish (US)
Pages (from-to)9545-9551
Number of pages7
JournalJournal of Materials Chemistry C
Issue number35
StatePublished - 2018

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: G. P. acknowledges DST-INSPIRE, Govt. of India for the Junior Research Fellowship award (DST INSPIRE-JRF IF#170198 DST/INSPIRE Fellowship/2016).


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