Pitfalls in Determining the Electrical Bandwidth of Non-Ideal Nanomaterials for Photodetection

TL;DR

This paper highlights the challenges and inaccuracies in measuring the electrical bandwidth of nanomaterial-based photodetectors, emphasizing the impact of non-idealities on response speed estimations.

Contribution

It reveals that common bandwidth measurement approaches can significantly misestimate response speeds for nanostructured photodetectors due to non-ideal behaviors.

Findings

Bandwidth deviations up to 10^3 times depending on measurement approach

Standard approximations are invalid for non-ideal nanomaterials

Careful measurement methods are essential for accurate response speed assessment

Abstract

The electrical 3 dB bandwidth is regularly used as a measure for the response speed of a photodetector and is estimated via various approaches in literature, ranging from direct measurements to gauged values via approximations. Great care must be taken when comparing these 3 dB bandwidths, since approximations are only strictly valid for ideal circuits. This paper demonstrates that, for typical photodetectors based on new emerging nanostructured materials, namely quantum dots and transition metal dichalcogenides, the bandwidth can deviate up to 10^3 depending on the chosen approach for the bandwidth specification.