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FemtoBlack

Project name:FemtoBlack – Femtosecond laser sulfur hyperdoped black silicon for infrared photonic applications
Department: Engineering – Applied Physics
Project lead:Prof. Dr. rer. nat. Stefan Kontermann
Project participants: 
Project partners:  
Duration:01.05.2020 – 31.12.2023
Funding body or client: Federal Ministry of Education and Research (BMBF), Internationalization for joint innovations in photonics

 

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Project description

Functionalising silicon is a way to obtain new material properties. Irradiating silicon with high-energy fs laser pulses simultaneously creates a surface structure of micro-cones up to 20 µm high, which traps light between the cones, and a sulfur-hyperdoped silicon layer close to the surface. This doping creates energy states within the silicon band gap that enable strong absorption of photons in the sub-band-gap range.

Photodetectors operating in the near-infrared spectral range are of great importance for spectroscopic applications and infrared thermal imaging. Silicon hyperdoped with sulfur using fs laser pulses (fs-hSi) shows high absorption in exactly this wavelength range and is therefore a promising material to replace expensive and often difficult-to-deposit infrared sensor materials such as InGaAs, InSb or HgCdTe.

Objective

FemtoBlack investigates the sensor-relevant properties of fs-hSi and of non-hyperdoped, fs-laser-processed black silicon (fs-bSi) in order to develop a suitable concept for implementing fs-hSi and fs-bSi in near-infrared sensors.

Project partners and tasks

  • InfraTec GmbH Infrarotsensorik und Messtechnik, Dresden: fs-hSi-based infrared sensors
  • Photonics Hub GmbH, Wörrstadt: acquisition of project partners in infrared sensor technology
  • Aalto University, Department of Electronics and Nanoengineering, Espoo (Finland): passivation of fs-hSi by atomic layer deposition
  • Beneq Oy, Espoo (Finland): development of ALD equipment
  • ElFys Oy, Espoo (Finland): fs-hSi- and fs-bSi-based infrared sensors
  • Noptel Oy, Oulu (Finland): optoelectronic distance and position sensors

Funding

FemtoBlack is funded by the German Federal Ministry of Education and Research (BMBF) under the measure “Internationalisation of leading-edge clusters, forward-looking projects and comparable networks” as part of the OptInt project (“Internationalization for joint innovations in photonics”). OptInt strengthens international cooperation between partners from research, development, production and application in photonics, and in particular improves the conditions for small and medium-sized enterprises to engage in cross-border research projects and marketable innovations.

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Poster

Project overview

Poster
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