Optical characterization labs at the division of solid state physics (FTF)

PL-CL lab

The labs are dedicated to studies of optical properties of semiconductor structures. These are located in separate labs (rooms). The capabilities include high spectral resolution; high temporal resolution; and high spatial resolution. The spectral range covered is from near infrared to deep UV. Most of the setups are equipped with low-temperature cryostats using liquid helium.

PL Labs: Consists of several labs with one or more setups in them. Mostly based of lasers for the excitation. i) Continuous wave excitation and spectrally resolved detection of luminescence, ii) Pulsed excitation and spectral and time resolved detection of luminescence, iii) Luminescence excitation spectroscopy, scanning the excitation energy while detecting a single energy. CL Lab: The excitation source is a scanning electron microscope (SEM) and it is used for spectrally resolved imaging at high spatial resolution.

The infrastructure as described here is an agglomeration of a number of separate labs with a similar type of characterization techniques. The labs are used, either directly or in collaboration by a large portion of the researchers at solid state physics. The number of researchers who depend on the infrastructure is therefore much larger than the actual number of users. Many of the labs are used for national and international collaborations.

The PL labs have four of setups: One for temperature dependent PL; one for excitation spectroscopy and Raman scattering; one for time-resolved spectroscopy including pump-probe experiments; and one simpler setup dedicated to the near infrared spectral region. The CL lab uses a conventional SEM (Zeiss EVO) with a Delmic Sparc light collection system, including a monochromator, a multi-wavelength CCD detector and several single wavelength photomultiplier tubes (PMTs). Spectral range is 200 nm to 1.7 µm (CCD 300 to 1.0µm) and optimal spatial resolution is 50 nm. Additionally, there are two Fourier transform infrared (FTIR) spectrometers, both from Bomem. They have a number of excitation sources and detectors.

Optical characterization of, mainly semiconductor structures.

All the setups generate digital data that is initially stored on the lab computers and optionally stored on an off-line server. This server is accessible from outside the labs whereas the lab computers are only accessible within the labs.

The optical characterization labs are run by individual managers, who are responsible for the running of the labs, including the planning, training, maintenance, and upgrading. The labs are the overall responsibility of the management of the division of solid state physics.