Near-infrared germanium PIN-photodiodes with >1A/W responsivity

Abstract Even though efficient near-infrared (NIR) detection is critical for numerous applications, state-of-the-art NIR detectors either suffer from limited capability of detecting incoming photons, i.e., have poor spectral responsivity, or are made of expensive group III-V non-CMOS compatible mate...

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Main Authors: Hanchen Liu, Toni P. Pasanen, Tsun Hang Fung, Joonas Isometsä, Antti Haarahiltunen, Steven Hesse, Lutz Werner, Ville Vähänissi, Hele Savin
Format: Article
Language:English
Published: Nature Publishing Group 2025-01-01
Series:Light: Science & Applications
Online Access:https://doi.org/10.1038/s41377-024-01670-4
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author Hanchen Liu
Toni P. Pasanen
Tsun Hang Fung
Joonas Isometsä
Antti Haarahiltunen
Steven Hesse
Lutz Werner
Ville Vähänissi
Hele Savin
author_facet Hanchen Liu
Toni P. Pasanen
Tsun Hang Fung
Joonas Isometsä
Antti Haarahiltunen
Steven Hesse
Lutz Werner
Ville Vähänissi
Hele Savin
author_sort Hanchen Liu
collection DOAJ
description Abstract Even though efficient near-infrared (NIR) detection is critical for numerous applications, state-of-the-art NIR detectors either suffer from limited capability of detecting incoming photons, i.e., have poor spectral responsivity, or are made of expensive group III-V non-CMOS compatible materials. Here we present a nanoengineered PIN-photodiode made of CMOS-compatible germanium (Ge) that achieves a verified external quantum efficiency (EQE) above 90% over a wide wavelength range (1.2–1.6 µm) at zero bias voltage at room temperature. For instance, at 1.55 µm, this corresponds to a responsivity of 1.15 A/W. In addition to the excellent spectral responsivity at NIR, the performance at visible and ultraviolet wavelengths remains high (EQE exceeds even 100% below 300 nm) resulting in an exceptionally wide spectral response range. The high performance is achieved by minimizing optical losses using surface nanostructures and electrical losses using both conformal atomic-layer-deposited aluminum oxide surface passivation and dielectric induced electric field -based carrier collection instead of conventional pn-junction. The dark current density of 76 µA/cm2 measured at a reverse bias of 5 V is lower than previously reported for Ge photodiodes. The presented results should have an immediate impact on the design and manufacturing of Ge photodiodes and NIR detection in general.
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spelling doaj-art-6785da8f16d34d638938b03956bca0652025-08-20T01:48:08ZengNature Publishing GroupLight: Science & Applications2047-75382025-01-011411810.1038/s41377-024-01670-4Near-infrared germanium PIN-photodiodes with >1A/W responsivityHanchen Liu0Toni P. Pasanen1Tsun Hang Fung2Joonas Isometsä3Antti Haarahiltunen4Steven Hesse5Lutz Werner6Ville Vähänissi7Hele Savin8Aalto University, Department of Electronics and NanoengineeringAalto University, Department of Electronics and NanoengineeringAalto University, Department of Electronics and NanoengineeringAalto University, Department of Electronics and NanoengineeringElFys, Inc.Physikalisch-Technische BundesanstaltPhysikalisch-Technische BundesanstaltAalto University, Department of Electronics and NanoengineeringAalto University, Department of Electronics and NanoengineeringAbstract Even though efficient near-infrared (NIR) detection is critical for numerous applications, state-of-the-art NIR detectors either suffer from limited capability of detecting incoming photons, i.e., have poor spectral responsivity, or are made of expensive group III-V non-CMOS compatible materials. Here we present a nanoengineered PIN-photodiode made of CMOS-compatible germanium (Ge) that achieves a verified external quantum efficiency (EQE) above 90% over a wide wavelength range (1.2–1.6 µm) at zero bias voltage at room temperature. For instance, at 1.55 µm, this corresponds to a responsivity of 1.15 A/W. In addition to the excellent spectral responsivity at NIR, the performance at visible and ultraviolet wavelengths remains high (EQE exceeds even 100% below 300 nm) resulting in an exceptionally wide spectral response range. The high performance is achieved by minimizing optical losses using surface nanostructures and electrical losses using both conformal atomic-layer-deposited aluminum oxide surface passivation and dielectric induced electric field -based carrier collection instead of conventional pn-junction. The dark current density of 76 µA/cm2 measured at a reverse bias of 5 V is lower than previously reported for Ge photodiodes. The presented results should have an immediate impact on the design and manufacturing of Ge photodiodes and NIR detection in general.https://doi.org/10.1038/s41377-024-01670-4
spellingShingle Hanchen Liu
Toni P. Pasanen
Tsun Hang Fung
Joonas Isometsä
Antti Haarahiltunen
Steven Hesse
Lutz Werner
Ville Vähänissi
Hele Savin
Near-infrared germanium PIN-photodiodes with >1A/W responsivity
Light: Science & Applications
title Near-infrared germanium PIN-photodiodes with >1A/W responsivity
title_full Near-infrared germanium PIN-photodiodes with >1A/W responsivity
title_fullStr Near-infrared germanium PIN-photodiodes with >1A/W responsivity
title_full_unstemmed Near-infrared germanium PIN-photodiodes with >1A/W responsivity
title_short Near-infrared germanium PIN-photodiodes with >1A/W responsivity
title_sort near infrared germanium pin photodiodes with 1a w responsivity
url https://doi.org/10.1038/s41377-024-01670-4
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