Tuning the gain-bandwidth product of electron Injector photodetectors

Simone Bianconi, Mohsen Rezaei, Hooman Mohseni*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Electron injector (EI) technology has already been proven capable of achieving unprecedented sensitivity in the shortwave infrared (SWIR), surpassing the current performance of commercial cameras. As on-chip optical interconnects have drawn increasing attention over the past few years, the need for energy-efficient (<10 fJ/bit) and fast (<10 Gbps) IR receivers has spurred new interest in detectors that can meet such requirements. However, heterojunction phototransistors typically suffer from a large power dependence of the gain-bandwidth product, which constitutes an intrinsic limitation to the realization of high-sensitivity, high-bandwidth photodetectors. We present a comprehensive analysis of the gain and bandwidth of the EI detectors as a function of optical power, for different device architectures. At low light level, as the optical power level increases, the recombination centers in the base are saturated by the higher excess carrier density, and as a result the gain-bandwidth product increases. At higher light level, however, the gain of the phototransistor drastically drops due to Kirk effect. As a result, the gain-bandwidth product peaks at a given power level, which is dependent on the band alignment, doping and defect density in the base. The presented results demonstrate a wide tunability of the EI detectors gain-bandwidth product as a function of the device architecture, and hence constitute a valuable platform for the design of novel detectors that can simultaneously achieve high sensitivity and high bandwidth at the desired optical power level depending on the envisaged application.

Original languageEnglish (US)
Title of host publicationQuantum Sensing and Nano Electronics and Photonics XVI
EditorsManijeh Razeghi, Jay S. Lewis, Eric Tournie, Giti A. Khodaparast
ISBN (Electronic)9781510624948
StatePublished - 2019
EventQuantum Sensing and Nano Electronics and Photonics XVI 2019 - San Francisco, United States
Duration: Feb 3 2019Feb 7 2019

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceQuantum Sensing and Nano Electronics and Photonics XVI 2019
Country/TerritoryUnited States
CitySan Francisco


  • Electron Injector detector
  • High bandwidth SWIR detector
  • Infrared imaging
  • Infrared optical receiver

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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