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 = -0.01129x + 476.1661 Eg A1g y = -0.0203 x + 635.0695 B2g y = -0.0180 x + 775.8361 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://www.researchgate.net/publication/320035132_Spectroscopic_Insights_i 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