Substrate Effects on the Speed Limiting Factor of WSe\(_2\) Photodetectors

We investigate the time-resolved photoelectric response of WSe\(_2\) crystals on common glass and flexible polyimide substrates to determine the effect of the dielectric environment on the speed of the photodetectors. We show that varying the substrate material can alter the speed-limiting mechanism...

Full description

Saved in:
Bibliographic Details
Published inarXiv.org
Main Authors Schedel, Christine, Strauß, Fabian, Kohlschreiber, Pia, Geladari, Olympia, Meixner, Alfred J, Scheele, Marcus
Format Paper
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 26.03.2022
Subjects
Depletion
Diffusion layers
Diffusion rate
Electric fields
Glass substrates
Limiting factors
Photoelectricity
Photometers
Online AccessGet full text

Cover

More Information
Summary:We investigate the time-resolved photoelectric response of WSe\(_2\) crystals on common glass and flexible polyimide substrates to determine the effect of the dielectric environment on the speed of the photodetectors. We show that varying the substrate material can alter the speed-limiting mechanism: while the detectors on polyimide are RC limited, those on glass are limited by slower excitonic diffusion processes. We attribute this to a shortening of the depletion layer at the metal electrode/WSe2 interface caused by the higher dielectric screening of glass compared to polyimide. The photodetectors on glass show a tunable bandwidth which can be increased to 2.6 MHz with increasing the electric field.
ISSN:2331-8422
DOI:10.48550/arxiv.2203.14053