Nanoplasmonic Semiconductor Light Detector — Device Design, Fabrication & Optimisation

About the Project

This PhD focuses on developing a working photodetector that uses a nanoplasmonic semiconductor composite as the active material. Unlike conventional detectors, these composites offer extended spectral sensitivity beyond the semiconductor bandgap, enhanced responsivity (A/W) through localised surface plasmon (LSP) field amplification, and ultrabroad bandwidth for high-speed operation.

The core fabrication route—nanoporous silicon scaffolds with embedded plasmonic nanoparticles via electroless/immersion plating—is established, but now requires optimisation for photodetection. You will engineer the composite to maximise responsivity, minimise noise, and enable fast, stable readout. This involves tuning porosity, particle size, and plasmonic resonance to match target wavelengths, while integrating electrical contacts and low-noise readout electronics.

Your challenge is to translate the known composite process into a complete detector architecture, including optical and electrical interfaces, packaging, and rigorous performance testing. The outcome will be a prototype device demonstrating the full potential of nanoplasmonic-semiconductor technology for next-generation photonic sensing.

Aims & Milestones

• Design the detector stack: optical entrance window, nanoplasmonic absorber layer, carrier collection/contact scheme, and low-noise readout.
• Tune fabrication for detection: control porosity, particle size/density, and plasmonic resonance for VIS–NIR/SWIR bands.
• Benchmark performance: responsivity (A/W), NEP, detectivity (D*), bandwidth, linearity, dark current, stability.
• Iterate & optimise: materials/process adjustments; thermal/optical modelling; reliability tests; device packaging.
• Demonstrate applications: fast imaging/sensing and SERS-assisted detection variants.

What You’ll Do

• Adapt the immersion-plating np-Si/Au process for device-grade uniformity.
• Pattern contacts and interconnects; develop low-noise electronics/FPGA-based acquisition (optional).
• Characterise spectral response and temporal dynamics (ultrafast pump–probe) and measure detector figures of merit.
• Model plasmon–semiconductor coupling and carrier transport; guide fabrication choices.
• Validate in lab demonstrators and prepare a prototype for user testing.

Training & Environment

• Nanofabrication (cleanroom), porous silicon lab, SEM/TEM, optical spectroscopy, ultrafast lasers.
• Device testing: calibrated sources, lock-in techniques, bandwidth/linearity, noise measurements.
• Optional firmware/data: FPGA/SystemVerilog, Python signal processing.
• Collaborations with photonics/industry partners; pathways to commercialisation.

Impact

Deliver a new detector class leveraging plasmonic enhancement for cost-effective, fast, and sensitive light measurement, with extended spectral response and broadband operation.

Candidate Profile

Physics/EE/Materials/Nanotechnology background; interest in detectors and plasmonics.

Equality, Diversity & Inclusion

The School of Physics and Astronomy is an Institute of Physics Juno Champion since 2014 and holder of the Athena SWAN Silver Award. We welcome applications from all qualified applicants and encourage applications from traditionally under-represented groups in physics and astronomy, including women and Black, Asian and Minority Ethnic.

How to Apply

Apply via the University of Birmingham portal with:

• CV
• Academic transcripts
• 1-page statement of research interests

Start date: October 2026

Informal enquiries: Dr Andre Kaplan – a.kaplan.1@bham.ac.uk