Fast and efficient Sb-based type-II phototransistors integrated on silicon

Increasing the energy efficiency and reducing the footprint of on-chip photodetectors enable dense optical interconnects for emerging computational and sensing applications. While heterojunction phototransistors (HPTs) exhibit high energy efficiency and negligible excess noise factor, their gain-ban...

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Main Authors: Lining Liu, Simone Bianconi, Skyler Wheaton, Nathaniel Coirier, Farah Fahim, Hooman Mohseni
Format: Article
Language:English
Published: AIP Publishing LLC 2025-03-01
Series:APL Photonics
Online Access:http://dx.doi.org/10.1063/5.0233887
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author Lining Liu
Simone Bianconi
Skyler Wheaton
Nathaniel Coirier
Farah Fahim
Hooman Mohseni
author_facet Lining Liu
Simone Bianconi
Skyler Wheaton
Nathaniel Coirier
Farah Fahim
Hooman Mohseni
author_sort Lining Liu
collection DOAJ
description Increasing the energy efficiency and reducing the footprint of on-chip photodetectors enable dense optical interconnects for emerging computational and sensing applications. While heterojunction phototransistors (HPTs) exhibit high energy efficiency and negligible excess noise factor, their gain-bandwidth product (GBP) has been inferior to that of avalanche photodiodes at low optical powers. Here, we demonstrate that utilizing type-II energy band alignment in an Sb-based HPT results in six times smaller junction capacitance per unit area and a significantly higher GBP at low optical powers. These type-II HPTs were scaled down to 2 μm in diameter and fully integrated with photonic waveguides on silicon. Thanks to their extremely low dark current and high internal gain, these devices exhibit a GBP similar to the best avalanche devices (∼270 GHz) but with one order of magnitude better energy efficiency. Their energy consumption is about 5 fJ/bit at 3.2 Gbps, with an error rate below 10−9 at −25 dBm optical power at 1550 nm. These features suggest new opportunities for creating highly efficient and compact optical receivers based on phototransistors with type-II band alignment.
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issn 2378-0967
language English
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publisher AIP Publishing LLC
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series APL Photonics
spelling doaj-art-bbbffe8b3dc14ba887fb338cb77940a82025-08-20T03:06:18ZengAIP Publishing LLCAPL Photonics2378-09672025-03-01103036106036106-910.1063/5.0233887Fast and efficient Sb-based type-II phototransistors integrated on siliconLining Liu0Simone Bianconi1Skyler Wheaton2Nathaniel Coirier3Farah Fahim4Hooman Mohseni5Bio-Inspired Sensors and Optoelectronics Laboratory, Northwestern University, 2145 Sheridan Rd, Evanston, Illinois 60208, USABio-Inspired Sensors and Optoelectronics Laboratory, Northwestern University, 2145 Sheridan Rd, Evanston, Illinois 60208, USABio-Inspired Sensors and Optoelectronics Laboratory, Northwestern University, 2145 Sheridan Rd, Evanston, Illinois 60208, USABio-Inspired Sensors and Optoelectronics Laboratory, Northwestern University, 2145 Sheridan Rd, Evanston, Illinois 60208, USAASIC Development Group, Particle Physics Division, Fermi National Accelerator, Batavia, Illinois 60510, USABio-Inspired Sensors and Optoelectronics Laboratory, Northwestern University, 2145 Sheridan Rd, Evanston, Illinois 60208, USAIncreasing the energy efficiency and reducing the footprint of on-chip photodetectors enable dense optical interconnects for emerging computational and sensing applications. While heterojunction phototransistors (HPTs) exhibit high energy efficiency and negligible excess noise factor, their gain-bandwidth product (GBP) has been inferior to that of avalanche photodiodes at low optical powers. Here, we demonstrate that utilizing type-II energy band alignment in an Sb-based HPT results in six times smaller junction capacitance per unit area and a significantly higher GBP at low optical powers. These type-II HPTs were scaled down to 2 μm in diameter and fully integrated with photonic waveguides on silicon. Thanks to their extremely low dark current and high internal gain, these devices exhibit a GBP similar to the best avalanche devices (∼270 GHz) but with one order of magnitude better energy efficiency. Their energy consumption is about 5 fJ/bit at 3.2 Gbps, with an error rate below 10−9 at −25 dBm optical power at 1550 nm. These features suggest new opportunities for creating highly efficient and compact optical receivers based on phototransistors with type-II band alignment.http://dx.doi.org/10.1063/5.0233887
spellingShingle Lining Liu
Simone Bianconi
Skyler Wheaton
Nathaniel Coirier
Farah Fahim
Hooman Mohseni
Fast and efficient Sb-based type-II phototransistors integrated on silicon
APL Photonics
title Fast and efficient Sb-based type-II phototransistors integrated on silicon
title_full Fast and efficient Sb-based type-II phototransistors integrated on silicon
title_fullStr Fast and efficient Sb-based type-II phototransistors integrated on silicon
title_full_unstemmed Fast and efficient Sb-based type-II phototransistors integrated on silicon
title_short Fast and efficient Sb-based type-II phototransistors integrated on silicon
title_sort fast and efficient sb based type ii phototransistors integrated on silicon
url http://dx.doi.org/10.1063/5.0233887
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AT skylerwheaton fastandefficientsbbasedtypeiiphototransistorsintegratedonsilicon
AT nathanielcoirier fastandefficientsbbasedtypeiiphototransistorsintegratedonsilicon
AT farahfahim fastandefficientsbbasedtypeiiphototransistorsintegratedonsilicon
AT hoomanmohseni fastandefficientsbbasedtypeiiphototransistorsintegratedonsilicon