Engineer­ing Graphene Photo­tran­sis­tors for High Dynamic Range Applicationsh

Shadi Nashashibi, Young Researcher of the Hector Fellow Academy, is first author of the publi­ca­tion “Engineer­ing Graphene Photo­tran­sis­tors for High Dynamic Range Appli­ca­tions”, which was published in May 2024 in the journal ACS Nano. During his work, he was super­vised by Hector Fellow Prof. Dr. Jürg Leuthold. The study focuses on a graphene-based photo­tran­sis­tor that utilizes the photo­gat­ing effect and exhibits photode­tec­tion in the picow­att to microwatt range.

he proposed device offers the highest dynamic range and lowest detected optical power compared to the state of the art in inter­fa­cial photo­gat­ing and is also air stable. Optimiza­tion of the device geome­try and the addition of a semi-trans­par­ent top gate allows a 20- to 30-fold improve­ment in sensi­tiv­ity. It also provides more degrees of freedom to tune the device perfor­mance to its ideal operat­ing point. The device geome­try is optimized with respect to the aspect ratio of the graphene channel, which can be used to improve photode­tec­tion performance.

These features are not limited to inter­face photode­tec­tors, but can be adapted to a variety of photo­gate devices. These combined capabil­i­ties are valuable for appli­ca­tions that require a high dynamic range, such as artifi­cial vision and vision restora­tion, and has poten­tial for bio-inspired appli­ca­tions such as retinal implants.