Decca, Ricardo S.Hua, MuchuanLi, TongcangCheng, RuihuaJoglekar, Yogesh N.Liu, Jing2019-09-202019-09-202019-12https://hdl.handle.net/1805/20964http://dx.doi.org/10.7912/C2/2432Indiana University-Purdue University Indianapolis (IUPUI)Optical refrigeration in quantum dots was carried out in this research. Zinc-blende crystalline CdSe/CdS (core/shell structure) QDs with complete surface passivation were synthesized and been used as the cooling substance. Phonon-assisted up-conversion photoluminescence driven by sub-band gap laser excitation was utilized as the cooling mechanism in the QD samples. A net cooling efficiency was predicted by a semi-empirical model developed during the research, within a range of the laser excitation energy, even after taking into account possible parasitic heating processes. To observe the cooling effect, the experiment was carried out in a thermally isolated environment, which temperature was also monitored. By using an optical thermometry technique developed for this research, a maximum temperature drop around 0.68 K was observed in the experiment. This development paves the way to use QDs' cooling in new industrial and fundamental research approaches.en-USAttribution 3.0 United Statesoptical refrigerationquantum dotsThesis