Lead Sulfide Quantum Dot Band Gap Investigations J
Lead Sulfide Quantum Dot Band Gap Investigations J. Ryan Peterson Thanks to: Dr. John S. Colton (advisor) Kameron Hansen, Luis Perez, Cameron Olsen
Quantum Dot Synthesis Different core sizes
Band gap distribution FWHM: 0. 3 e. V FWHM: 0. 007 e. V
Varying Band Gap Energy Using the Brus Equation Pb. S quantum dot band gap Bulk Pb. S band gap
Photoluminescence Experimental Setup 398 nm Diode Laser Sample 0. 25 m Spectrometer and Germanium Detector
Pb. S Photoluminescence Signal adjusted for system sensitivity Measured signal Half max Measured signal
Size and Band Gap Results Sample Measured Radius Expected Band Gap (Brus equation) Measured Band Gap and FWHM Sample 1 2. 25 ± 0. 48 nm 1. 70 e. V (1. 29 e. V - 2. 50 e. V) 1. 33 e. V (0. 33 e. V) Sample 2 3. 03 ± 0. 39 nm 1. 12 e. V (. 97 e. V – 1. 35 e. V) 1. 14 e. V (0. 31 e. V) Sample 3 3. 04 ± 0. 54 nm 1. 12 e. V (. 92 e. V – 1. 46 e. V) 1. 23 e. V (0. 23 e. V) Sample 4 5. 70 ± 0. 89 nm 0. 61 e. V (. 56 e. V -. 69 e. V) 1. 0 e. V (0. 3 e. V) Sample 5 6. 10 ± 0. 89 nm 0. 59 e. V (. 54 e. V -. 65 e. V) < 1. 0 e. V
Protection Against Photocorrosion Catalysis Science & Technology, 2013, 3, 3103
Thioglycerol Pb. S Time-Dependent PL Spectra taken at 5 minute intervals
Ferritin Pb. S Time-Dependent PL
Thioglycerol Pb. S Photocorrosion Before Thioglycerol-capped Pb. S Ferritin-enclosed Pb. S After
Conclusions and Future Work • Ferritin core size and band gap widely tunable • Ferritin effectively protects against photocorrosion FTN-Pb. S 3 hours Thio-Pb. S 3 hours
Measurement limits Detector Response Signal adjusted for system sensitivity Half max Measured signal
Ferritin Pb. S Time-Dependent PL 1. 2 e. V
Thioglycerol Pb. S Photocorrosion Thioglycerol-capped Pb. S Ferritin-enclosed Pb. S
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