English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Graphene is a promising material for ultrafast and broadband photodetection.Earlier studies addressed the general operation of graphene-basedphoto-thermoelectric devices, and the switching speed, which is limited by thecharge carrier cooling time, on the order of picoseconds. However, thegeneration of the photovoltage could occur at a much faster time scale, as itis associated with the carrier heating time. Here, we measure the photovoltagegeneration time and find it to be faster than 50 femtoseconds. As aproof-of-principle application of this ultrafast photodetector, we use grapheneto directly measure, electrically, the pulse duration of a sub-50 femtosecondlaser pulse. The observation that carrier heating is ultrafast suggests thatenergy from absorbed photons can be efficiently transferred to carrier heat. Tostudy this, we examine the spectral response and find a constant spectralresponsivity between 500 and 1500 nm. This is consistent with efficientelectron heating. These results are promising for ultrafast femtosecond andbroadband photodetector applications.

Generation of photovoltage in graphene on a femtosecond time scale through efficient carrier heating