SATPC0035960 Tab 04 5 SOW.pdf

SSttaatteemmeenntt ooff tthhee wwoorrkk ((SSOOWW))

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The overall statement of the program is to fabricate the sample and study in details the point and line defects using microscopic and emission characteristics. The detailed work involves the study of the microstructures at low and high magnifications to evaluate precipitates, voids and line defects in the crystals and effects of these defects on the performance of crystals. The performance requires the capabilities to measure the optic absorbance, emissions, luminescence (cryogenic temperature), Raman spectroscopy, and electrical characteristics such as bandgap and effects of defects and dopant on the bandgaps as well as to correlate these measured results to understand the overall picture of the defects. To achieve these goals, contactor should perform a combination of tasks and should have unique and necessary equipment. The contractor will perform the following tasks to meet the goals of the program.

Task 1. Fabricate samples for microscopic, and optical characterization using techniques suitable for pure and doped zinc selenide provided by NASA Marshall Space Flight Center.

Task 2. Develop optical and electrical characterization matrix for the fabricated samples

Task 3. Determine optical absorbance and determine bandgap and residual impurities so that optical bands can be identified. The characterization techniques, such as high-resolution Scanning

Electron Microscope (SEM) and Energy Dispersive of X-ray (EDX), for determining morphology and properties should be used by contractor.

Task 4. Develop data on the luminescence at room temperature and cryogenic temperature using known excitation wavelength of lasers in at least two wavelength regions. For example, 400-

600nm and 700-800nm excitation wavelength and known filter to block unwanted wavelength. To evaluate the defects Raman studies will be performed and defects due to doping and process parameters (including role of convection) should be evaluated. For this task contractor should use lasers and cryogenic facilities.

Task 5. Correlate data with defects and performance and discuss with Program Manager to make matrix for developing role of convection to feed into microgravity experiments. The contractor will participate, coordinate, and direct all tasks of the program. The Principal Investigator will make plans and act accordingly to meet the goals of the program.

Task 6: The students will prepare measurement systems for the photoluminescence study of the pure and doped ZnSe crystals provided by NASA Marshall Space Flight Center.

Task 7: Provide the final report which should include presentations and publications after permission of the program manager and NASA.