1. Structure of the SnO2 crystal
Spectroscopic Characterization of Tin Dioxide Ben Concepcion, Dr. Prabhakar Misra, Ms. Hawazin Alghamdi
CONCLUSION
INTRODUCTION
RESULTS
SnO2 has many features including:
High Bandgap Energy
Useful in sensing dangerous gases
Thermal Reflecting
More work needs to be performed this summer to determine new information on the properties of SnO2. So far, data seems to agree with other literature which hints at promising future discoveries. Further numerical simulation will also be key in confirming and predicting experimental data.
SnO2 nanopowder at 30oC
Raman Shift (cm-1)
Amplitude (a.u.) Eg
A1g
B2g
Raman spectrum of SnO2 shows three distinct peaks from active Raman modes3.
FUTURE WORK
y = x Eg
A1g
y = x
B2g
y = x
Temperature dependence plots of peaks show a red shift with increasing temperature. Values are close to expected1,2.
Use existing UV Vis with broader range
FTIR contamination/noize
Attempt to restore other FTIR
Understanding structure/concentration
of films
Numerical simulation of SnO2 using LAMMPS
to predict vibrational frequencies at different temperatures
Structure of the SnO2 crystal
METHODS
Analyzed SnO2 using Raman
spectroscopy at temperatures
varying from room temperature
to 170 oC
SEM imaging of SnO2 grains
FTIR imaging of SnO2 films on
copper and UV quartz ranging from
78 nm to 908 nm
Calculated bandgap using
numerical methods with FTIR data
SnO2 on UV Quartz (78 nm)
SnO2 on UV Quartz (908 nm)
FTIR data was analyzed to find the bandgap energy. A linear fit to the end behavior of a plot of (Eα)2 vs E reveals the x-intercept as the bandgap value.
FTIR data proved to be problematic in many instances, and further scans need to be performed before conclusions are made about trends.
REFERENCES
1https://pdfs.semanticscholar.org/f113/232e40e632b7bd24d92905d3507b7d174 1a2.pdf
2Sergent, Epifani, Pagnier. J. Raman Spectrosc. 2006; 37: 1272–1277
3https:// n_the_Gas_Detection_Mechanism_of_Tin_Dioxide_Based_Gas_Sensors
Raman Spectrometer
ACKNOWLEDGEMENTS
Special thanks to Dr. Shankar Baliga for providing samples and data
Work performed in collaboration with Ms. Olasumbo Farinre, Ms. Lia Phillips, and Dr. David Casimir
SEM image of SnO2 grains