Scalable single-photon detection, from visible to SWIR.
Today's single-photon detectors force trade-offs between wavelength coverage, cooling, cost, and scalability. GeQD is developing a CMOS-compatible germanium-on-silicon SPAD platform targeting ~600–1550 nm operation to lift those constraints.
The Bottleneck
Single-photon detection still limits scalable photonic systems.
Single-photon applications increasingly need detection beyond the visible spectrum, particularly in the near-infrared and SWIR range. Today, no single detector technology combines wavelength coverage, room-temperature operation, scalability and the resulting declining unit-cost curve in one solution. Each established option solves only part of the problem.
Silicon SPADs
Mature, scalable, low-cost. Bottleneck: Absorption drops sharply beyond ~1 µm, leaving SWIR uncovered.
InGaAs / InP SPADs
Provide SWIR sensitivity around telecom wavelengths (1310 / 1550 nm). Bottleneck: Cost, gating and array scaling remain hard.
SNSPDs
Excellent efficiency, timing and dark-count performance. Bottleneck: Cryogenic infrastructure restricts deployment to specialized environments.
To scale single-photon systems beyond specialized labs, detector technology must become easier to manufacture, easier to integrate, and easier to operate.
No existing solution combines SWIR sensitivity , room-temperature operation , CMOS scalability , industrial viability .
The Solution
Germanium-on-silicon SPADs, built for scale.
GeQD is developing a single-photon detector platform that uses germanium as the absorption material, extending sensitivity into the near-infrared and SWIR range — well beyond the reach of silicon. GeQD SPADs are built on a silicon-compatible semiconductor process, combining SWIR photon absorption with scalable manufacturing and integration with CMOS readout electronics.
Targeting visible-to-SWIR sensitivity
≈ 600 – 1550 nm
Germanium absorber for SWIR reach
One material platform across the band
Designed for room-temperature operation
No cryogenics in the target design
Avoids cryostat-bound deployment
Targeting compact, system-friendly modules
Enabling a path toward CMOS-scale integration
Silicon-compatible process
Compatible with CMOS readout
Foundation for future arrays
GeQD targets scalability, SWIR detection and system integration in one platform
Detector type
Wavelength
Cooling
Scalability
Cost
Key limitation
Silicon SPAD
Visible / NIR
Room temperature
High
Low
Weak beyond ~1 µm. Blind in SWIR.
InGaAs / InP SPAD
900–1700 nm
Often cooled / gated
Limited
Cost, integration, afterpulsing
SNSPD
Broadband
Cryogenic (~1–4 K)
Very high
Cooling & infrastructure overhead
GeQD Ge-on-Si SPAD
600–1550 nm
Room temperature Not yet demonstrated
CMOS-compatible
Low (competitive with Silicon SPADs at scale)
LabOne at TRL 4 today — TRL 5 targeted for 2027/2028
Wavelength range and CMOS compatibility are inherent properties of the Ge-on-Si platform. Cost parity with Silicon SPADs follows from CMOS processing at scale. Room-temperature operation at the targeted performance is the goal but has not yet been demonstrated; the TRL milestone is a roadmap target.
How a detection event happens
A single photon in the visible-to-SWIR range enters the detector.
Germanium absorbs the photon and converts it into an electron-hole pair.
The charge carrier is accelerated and triggers an avalanche of carriers.
Built on a silicon substrate compatible with semiconductor manufacturing flows.
Standard CMOS electronics convert the avalanche into a clean electrical pulse.
A timestamped digital event is delivered to the host system.
Simplified Ge-on-Si SPAD layer structure
Performance parameters
Characterisation of the current detector generation is ongoing. The table shows the status per parameter; measured data is shared under NDA.
Parameter
Status
Photon detection efficiency (PDE)
Characterisation in progress
Dark count rate (DCR)
Timing jitter
Afterpulsing probability
Dead time
Operating temperature
TEC-cooled demonstrators; room temperature as development target
Array scalability
Single pixels and test arrays; array scaling in development
Values will be published as characterization data is consolidated. GeQD reports parameters from internal lab measurements unless otherwise indicated.
From this platform, GeQD is developing detector modules and arrays for quantum, sensing and photonic test applications.
Germanium-on-silicon SPAD platform · room-temperature target · CMOS-compatible · 600–1550 nm
Prototypes
Our Prototypes
From lab modules toward application-ready systems, developed for practical use in the laboratory.
GeQD LabOne
4-Channel SWIR SPAD Module
A compact single-photon detection module for quantum research and industrial prototyping.
Easy handling (Plug-and-Play)
Weight & size efficient
Integration into customer-specific applications
4-channel SWIR SPAD
Fiber-coupled, room-temperature target
Ge vs InGaAs vs Si
Daylight
Range
GeQD range ≈ 4× of Si (model-based target — not yet demonstrated)
Rain & Fog
GeQD range ≈ 3× of Si (model-based target — not yet demonstrated)
Cost
(lower = better)
GeQD ~10× cheaper than InGaAs and close to Si (model-based projection at scale — not yet validated)
* Model-based target values derived from laboratory measurement data; not yet demonstrated in field tests.
Wavelength Advantage
Same scene, two detectors. 1550 nm Ge-SPADs return a denser point cloud and reach further than 905 nm silicon — across day, night, and adverse weather.
* Based on calculations from the laboratory demonstrator.
Eye-Safe
1550 nm is inherently eye-safe
Higher Range
Reaches further at eye-safe power
All-Weather
Better fog & rain penetration
VisionOne
SPAD Array Platform
A scalable SPAD array platform for automotive LiDAR and industrial sensing applications.
High performance and scalability
Weight & size efficient for versatile system integration
Room-temperature operation (target)
Applications
Enabling the Next Generation of Photon-Based Systems
Quantum Technologies
Quantum key distribution (QKD)
Multi-photon experiments
Quantum sensing
LiDAR
1550 nm eye-safe operation
Potential reach of up to ~400 m (model-based target — not yet demonstrated)
Automotive-grade scalability (target)
Robotics & Automation
High-precision ToF sensing
Harsh condition reliability
Compact integration
Medical Imaging
Deep tissue SWIR detection
Time-resolved imaging
Future platform
Our Team
Built at the Intersection of Physics and Engineering
Four founders combining deep semiconductor expertise with entrepreneurial execution. Rooted at the University of Stuttgart.
University of Stuttgart Spin-Off
Click a profile to learn more.
Maurice Wanitzek
SPAD Device Design & Process Development
Leads SPAD device design and semiconductor process development for germanium-on-silicon detector structures. From device simulation through wafer-level characterization.
Dr. Maximilian Scheu
Commercialization & Venture Development
Leads market validation, funding strategy, partnerships, and venture development for GeQD, turning the detector platform into a fundable, commercially ready company.
Jakob Finkbeiner
ASIC & Readout Electronics
Leads ASIC and readout electronics design for the Ge-on-Si SPAD platform, including quenching, timing, and CMOS-compatible co-integration with the detector arrays.
Dr. Claudia Bett
Photonic Integration & System Design
Leads photonic integration and system-level design, covering coupling, packaging, and module-level integration of Ge-on-Si SPAD detectors into application photonic systems.
Traction
We turn scientific findings into a technology company.
Funding, process generations, market validation, and a defined roadmap — the indicators that GeQD is moving from research result to detector platform.
approx. €1.2 M
EXIST Forschungstransfer secured
BMWK-funded research transfer grant; runway until 02/2028.
Spin-off
Born from semiconductor & photonics research
Spin-off of the University of Stuttgart with access to labs and infrastructure and close collaboration with the Institute of Semiconductor Engineering , building on peer-reviewed Ge-on-Si SPAD research.
Iterative
Iterative semiconductor process improvements
Continuous iterative improvements of the Ge-on-Si SPAD semiconductor processes across multiple generations; the next iteration is currently in fabrication.
Prototype
Prototype & wafer iterations ongoing
Continuous device, wafer-process, and characterisation cycles in collaboration with IMS CHIPS .
Customer discovery across four target markets
Active discovery and discussions across QKD, LiDAR, SWIR imaging, and integrated photonic systems.
Member of QuantumBW and TUM Venture Labs
Member of the QuantumBW innovation network and of the TUM Venture Labs Quantum & Semiconductor programme.
IP
Background IP assigned · ASIC and array roadmap
Background IP assigned from the University of Stuttgart to the founding team — an assignment, not a license. First patent application in preparation. The GeQD word mark has been filed. ASIC/readout and array scaling roadmap defined for the next product generations.
Next 2 years
Clear technological milestones
Characterisation and further development of the semiconductor processes, ASIC/readout integration, array demonstrators, and pilot evaluations.
Status as of 08/2026. Active discovery and discussions are non-binding expressions of interest from research groups and industry partners.
Get in touch
Three ways to engage with GeQD.
Pick the path that matches your intent — pilot evaluation, investor diligence, or joining the team.
Explore detector pilots
Work with GeQD to evaluate whether germanium-on-silicon SPAD technology fits your QKD, LiDAR, SWIR sensing, or photonic system requirements.
Follow the roadmap
GeQD is developing a semiconductor detector platform with clear technical milestones across wavelength response, dark count, timing, array scaling, and manufacturability.
Build the detector platform
Join a deep-tech team working at the intersection of semiconductor devices, photonics, quantum technology, and scalable manufacturing.
Universität Stuttgart – Institut für Halbleitertechnik
Contact
Pfaffenwaldring 47
70569 Stuttgart, Deutschland
Tel: +49 711 68560896
info@geqd.de
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