Infrared detectors using monolithically integrated doped semiconductor “designer metals” are proposed and experimentally demonstrated. We leverage the “designer metal” groundplanes to form resonant cavities with enhanced absorption tuned across the long-wave infrared (LWIR). Detectors are designed with two target absorption enhancement wavelengths: 8 and 10 μm. The core of our detectors are quantum-engineered LWIR type-II superlattice p-i-n detectors with total thicknesses of only 1.42 and 1.80 μm for the 8 and 10 μm absorption enhancement devices, respectively. Our 8 and 10 μm structures show peak external quantum efficiencies of 45 and 27%, which are 4.5× and 2.7× enhanced, respectively, compared to control structures. We demonstrate the clear advantages of this detector architecture, both in terms of ease of growth/fabrication and enhanced device performance. The proposed architecture is absorber- and device-structure agnostic, much thinner than state-of-the-art LWIR T2SLs, and offers the opportunity for the integration of low dark current LWIR detector architectures for significant enhancement of IR detectivity.
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Subwavelength antimonide infrared detector coupled with dielectric resonator antenna
Antenna coupled detectors break the intrinsic tradeoff between signal and noise by “collecting over a large area” and
“detecting over a small area”. Most antenna coupled detectors in the infrared rely on a metal resonator structure.
However, there are losses associated with metallic structures. We have demonstrated a novel long-wave infrared (LWIR)
detector that combines a dielectric resonator antenna with an antimonide-based absorber. The detector consists of a 3D,
subwavelength InAsSb absorber embedded in a resonant, cylindrical dielectric resonator antenna made of amorphous
silicon. This architecture enables the antimonide detection element to shrink to deep subwavelength dimensions, thereby
reducing its thermal noise. It is important to note that this concept only applies when (a) the detector noise is limited by
bulk noise mechanisms with negligible surface leakage currents and (b) the dominant source of current in the device is
due to dark current (such as diffusion) that scales with the volume of the detector. The dielectric resonator enhances the
collection of photons with its resonant structure that couples incident radiation to the detector. We will present results on
the absorption in structures with and without the dielectric resonator antenna. The signal to noise enhancement in the
LWIR photodiodes integrated with the dielectric resonator antenna using radiometric characterization will be discussed.
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- Award ID(s):
- 1806311
- NSF-PAR ID:
- 10152797
- Date Published:
- Journal Name:
- Subwavelength Antimonide Infrared Detector Coupled with Dielectric Resonator Antenna
- Volume:
- 11002
- Page Range / eLocation ID:
- 70
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Pyroelectric detectors are often broadband and require external filters for wavelength‐specific applications. This paper reports a tunable, narrowband, and lightweight pyroelectric infrared detector built upon a flexible membrane of As2S3−Ag−P(VDF‐TrFE) with subwavelength grating, which is capable of both on‐chip filtering and photopyroelectric energy conversion. The top surface of this hybrid membrane is a corrugated As2S3−Ag film contributing to narrowband light absorption in the near‐infrared (NIR) regime, and the bottom part is a polyvinylidene fluoride‐trifluoroethylene (PVDF‐TrFE) membrane for the conversion of the absorbed light to an electrical signal. Uniquely, applying a bias voltage to the PVDF‐TrFE membrane enables the tuning of the device's absorption and pyroelectric characteristics owing to the piezoelectrically induced mechanical bending. The resonator exhibited a resonant absorption coefficient of 80% and a full‐width‐half‐maximum of 15 nm within the NIR, a responsivity of 1.4 mV mW−1, and an equivalent noise power of 13 µW Hz−1/2at 1560 nm. By applying a 15‐V bias to the PVDF‐TrFE membrane, the absorption coefficient decreased to 18% due to the change in the grating period and incident angle. The narrowband and tunable features of the As2S3−Ag−P(VDF‐TrFE) pyroelectric detector will benefit a variety of potential applications in sensors, optical spectroscopy, and imaging.
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1117/12.2518807
