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UTA aSe Evaporator Overview

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Layout

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Crystal Quartz thickness monitor

Rotating sample stage

Stage heating element

Selenium heating system

Stage holder and heater

Selenium Crucible

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Process

  • Pump Chamber to Vacuum (~10-5 Torr)
  • Preheat Stage to 60C
  • Rotate Stage at 50 RPM
  • Slowly Heat Crucible to ~ 200C
  • Control Temp to maintain growth rate of ~ 2.5 Å/s
  • When finished stop rotation and set Stage to 40C
  • Leave for 24 hours with lights off

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Results

Ours

Michael’s

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Optical Microscope

Ours

Michael’s

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Optical Microscope (10x)

Ours

Michael’s

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SEM Comparison

Ours

Michael’s

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Raman Comparison

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XRD

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EDS Comparison

Ours

Michael’s

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Conclusion

  • Raman and XRD suggests we have amorphous selenium
  • EDS shows similar elemental compositions
  • However, have much worse film quality
  • Would welcome any advice to our setup/process to achieve a better film