Carrier Dynamics Characterisation in Wide and Narrow Bandgap Semiconductors
Photonic Integrated Circuits
Technical Scope and Capabilities
This service provides characterisation of non-equilibrium charge carrier dynamics in organic or inorganic, wide or narrow bandgap semiconductors.
The service evaluates excitation-energy-density-dependent parameters including
The full characterisation includes
- ambipolar diffusion coefficient
- lifetime
- diffusion length
- quantum efficiency
- peak emission position.
- light-induced transient grating measurements
- time-integrated photoluminescence measurements
- ABC modelling.
Partial characterisation may include:
- LITG measurements for diffusion coefficient, lifetime and diffusion length
- TIPL measurements for quantum efficiency and spectral parameter extraction
- ABC simulations only, if the client provides the necessary carrier dynamics data.
Core Infrastructure / Tools / Equipment
The service uses
- PHAROS laser, 6 W, 30 kHz, approximately 250 fs pulse duration, 1030 nm central wavelength
- ORPHEUS optical parametric amplifier with wavelengths of 257 nm or 300–2600 nm
- Thorlabs CCD camera
- Nova 2 power meter
- HARPIA-TG spectrometer for LITG measurements
- Avaspec 2048 spectrometer and 6-inch BaSO₄-coated integrating sphere for TIPL measurements
- default equipment software and in-house Python code.
Substrate Polishing
Substrate polishing can be provided, for example for sapphire or silicon, to achieve optically smooth surfaces for measurements requiring beam transmission. Polishing is performed using a UNIPOL-300 automatic machine.
Out-of-the-Lab Measurements
An out-of-the-lab service may be available when a researcher performs measurements on local equipment at another facility, specifically using the HARPIA-TG spectrometer.
Possible Restrictions
For LITG measurements, samples must be transparent to the 1030 nm probe. Increasing the probe wavelength is possible but must be discussed individually. The substrate side should be optically smooth.