Nanostructure Materials & Devices Laboratory
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     The NMDL has extensive facilities for the synthesis, in-situ processing, structural, electrical, and optical characterization of semiconductor nanostructures. Given our activity in nanocrystal quantum dots and biochemical/ inorganic hybrid nanostructures, facilities for the synthesis and characterization of such materials and structures are also available.

All UHV Interconnected Growth & In-Situ Processing, & Characterization System

      We have a unique all UHV interconnected molecular beam epitaxical growth, processing, and in-situ UHV STM/AFM characterization system. A picture and schematic are shown below. This system is a 6 chamber interconnected system comprised of (1) an MBE growth chamber for III-Vs, (2) a Fluoride MBE and metallization chamber, (3) a plasma enhanced chemical vapor deposition (PECVD) system for dielectric deposition, (4) a focused ion beam (FIB) system for pattern generation via ion-assisted reactive dry etching, (5) an electron cyclotron resonance (ECR) etching system for low energy parallel etching of the semiconductor through the patterned windows opened by the FIB, and (6) an UHV AFM/STM system for in-situ nanoscale characterization. This system has been the basis of NMDL's work on in-situ characterization of the InGaAs/AlGaAs SAQDs and in-situ nanostructure synthesis of MTSQDs via size-reducing growth on externally or in-situ FIB prepared mesas. Ex-situ photolithographic processing facilities are available at the John O'Brien Nanofabrication Laboratory.

Facilities for Quantum optical studies

     The quantum optical measurement facilities we have are state-of-art, suitable for studying single photon emission, photon interference and photon entanglement as well as quantum tomography of photons from on chip single photon emitters at temperature from 10K to room temperature (enabled by cryogen free cryostat). Such facility has been used to study our Mesa-Top Single Quantum Dots as a new class of on-chip spectrally uniform and spatially ordered single photon emitters.

      The facility contains (1) time-integrated photoluminescence with 15ueV resolution, (2) time-resolved photoluminescence with time resolution of ~100ps along with spectral resolution of 15ueV, (3) time-correlated photoluminescence containing both Hanbury Brown and Twiss (HBT), (4) unbalanced Mach-Zehnder interferometer and (5) Hong-Ou-Mandel (HOM) interferometer with timing resolution of ~100ps. Such instrumentation enables the study of single emission dynamics, correlation, and single-photon and two-photon interference.

      The facility has also been built with an imaging system to study the far field radiation pattern of single photon from MTSQDs for exploration of dipole orientation and orbital angular momentum of the emitted single photon for encoding quantum information. The state-of-art facilities are also capable of studying quantum tomography of any two to four photon states for study of photon entanglement and entanglement swapping.

Biochemical Synthesis and Characterization

     The Biochemical Nanostructure facility of the Nanostructure Materials and Devices Laboratory (NMDL) has the infrastructure and facilities required for conducting various biological work, biochemical synthesis and characterization studies. For biological work relating to preparation and storage of various cell lines, the facility is quite self reliant and encompasses all the relevant equipment such as a biological safety cabinet that provides a sterile environment for cell culture work and manipulation of other biologically sensitive substances, incubators needed for cell growth during culture, an autoclave needed for sterilizing of glassware, lab ware and media solutions, low-temperature freezers (-80°C and -20°C) and a 4°C refrigerator needed for the storage of competent cells, cell stocks, peptides, antibodies, fluorescent dyes, QD chemicals and other biological supplies. Other supporting equipment includes a water purification system that provides ultra high purity water, centrifuges, shakers, heat plates, balances, etc. For biochemical work relating to synthesis of various QDs, fluorescent markers and their bio-conjugation, it has a Glove box that provides a controlled inert Argon environment (< 3-4 ppm of H2O and O2) for performing environment sensitive reactions and a Fume Hood needed for performing other general chemical reactions. Quick Spectroscopic characterization and analysis of various biochemical and biological entities and constituents is enabled by a UV-Vis spectrophotometer. In addition to the above mentioned, it also has facilities for conducting various protein/DNA synthesis work such as protein gel-electrophoresis units for protein and peptide analysis, a Lyophilizer and a speed-vacuum system for protein purification

Structural Studies

     Ex-situ structural characterization via AFM and STM (including in liquid cell environment), and high resolution SEM is available. Analytical and high resolution transmission electron microscopy is available as part of central facilities in the Center for Electron Microscopy and Microanalysis (CEMMA).

Electrical Studies

     Facilities for Hall measurements, conductivity, tunneling, and capacitance-voltage measurements as a function of temperature from ~2K to ambient are available.

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