The lower the sample temperature, the sharper the absorption bands
Cryostation C2 is the perfect tool for low-temperature measurements of vibration-sensitive quantum systems. Quantum dots are stable light sources with a wide color spectrum. They are mainly used in consumer electronics. Further application fields include solar cells, where they are used as tunable absorbers, and research where they serve as single-photon source for quantum computers and quantum cryptography. The characteristic absorption and emission lines can be controlled by the particle size. Temperature also has a direct influence on the particle behavior. Measurements at low temperatures give thorough information on the behavior of these small structures. At room temperature, many effects are covered up by thermal energy and fine structures can not be resolved due to the high line width.
Measurements at low temperatures are often challenging. Cryostat cold heads may cause significant vibrations and quantum systems are often vibration sensitive. Cryostation C2 features an extremely stable sample stage with vibrations less than 5 nm peak-to-peak. The sample can be kept at a constant temperature over a long period of time, which allows the sample to be measured during days and weeks in a stable environment. The integrated microscope (NA: 0.9) allows the collection of twice as many photons as with the best external objective, which would have to be installed outside a cryostat. The extremely low drift of the sample stage allows long integration times that provide an outstanding signal-to-noise ratio.