InP/InGaAs Uni-Traveling-Carrier Photodiode (UTC-PD) with Improved EM Field Response

Maria Jabeen, Shyqyri Haxha, Ian Flint, Turgut Öztürk, Martin Charlton, Fathi AbdelMalek

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In this paper a unique structure of InP/InGaAs Uni-Traveling-Carrier Photodiode (UTC-PD) is proposed. Compared with the one-sided junction photodiode, the UTC-PD has the advantages of simpler epitaxial layer structure while maintaining the characteristics of high bandwidth and high output power loss profile. Simulated results show that a large built-in electric field can be generated under illumination which aids UTC carrier velocity. The merits of the new structure are compared to a standard UTC-PD photodiode in terms of improved electric field and carrier concentration response. It is demonstrated that the photogeneration and light absorption of UTC-PD's is improved by incorporating a step-like internal texture of cones and dots profile in the photo absorption layer. The simulated device shows a peak electrical 3-dB bandwidth of 65 GHz at a low light intensity and reverse bias voltage. The performance characteristics of 1D and 2D UTC-PD simulations including internal electric field distribution, energy band diagram, carrier concentration, and power loss distribution, are carefully studied. A theoretical discussion of the working principal and key performance characteristics of a UTC-PD enhanced by heterojunction design are reported. The entire physical environment is modelled and simulated through Finite Element Method (FEM) using commercial software. The proposed photodiode structure configuration is designed and optimised for photodetectors for high RF frequencies at different light intensities. To our knowledge, the obtained bandwidth and electric field response is the fastest among those reported for other various higher wavelength photodiodes.
Original languageEnglish
Pages (from-to)20438-20447
Number of pages10
JournalIEEE Sensors Journal
Issue number21
Publication statusPublished - 29 Sept 2022


  • Photodiode
  • InP/InGaAs Uni-Traveling-Carrier Photodiode (UTC-PD)
  • nano-junction

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