Nanomaterials Lab Facilities;


Molecular Beam Epitaxy (MBE): A commercial MBE machine (SVTA-35N) is dedicated to the fabrication of epitaxial nanostructures. It is equipped with residual gas analyzer (RGA), flux monitoring gauge, reflection high energy electron diffraction (RHEED) and ten source ports. The MBE growth is controlled by a dedicated computer which controls the whole growth process through a “recipe”.











Scanning Tunneling Microscope (STM): A commercial STM (Omicron 1) is attached to the MBE preparation chamber via vacuum port to characterize as-grown surface morphologies in atomic scale




Imaging station of STM: examples as-grown, as-patterned and as-cleaved surface images can be found at Image gallery.





High power laser system with a seeder laser: Continuum Surelite I-10 produces 7 nanosecond laser pulses at the first harmonics at 1064nm (400mJ per pulse), second 532nm (200mJ), third 355nm (100 mJ) and fourth harmonics at 266nm (50mJ). A seeder laser from NP Photonics is integrated into the laser head in order to extend the coherence length of the pulses for all harmonics.






Photoluminescence (PL) system: The PL system consists of an excitation source, Coherent CUBE laser emitting 405nm, a passive cryostat, Janis ST500 for sample cooling, a spectrometer, Horiba iHR320, a photodiode and a lock-in amplifier, Signal Recovery 7265. The light emission is directed to the InGaAs photo detector that feeds the signal to the Lock-In amplifier. Data collection is fully automated based on Lab-view codes written in house for controlling the stepping motor in the spectrometer and collecting signal from Lock-in amplifier. The PL system is used to characterize basic electronic structures of epitaxial nanostructures.



Raman system: The Renishaw Raman system sits adjacent to the PL system. It consists of an excitation sources, He-Ne laser and Argon Ion laser, spectrometer, optical microscope (Olympus BH-2), a stage controller, and a data acquisition computer.



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