Colloidal Synthesis of Germanium Chalcogenide Nanomaterials and Controllable Conversion of Plasmonic Cu2-xS Nanoparticles to Ag2S
MetadataShow full item record
Nanotechnology is still at an early stage of development in many respects. For example, synthesis of metal chalcogenide semiconductor nanomaterials is far from mature. Advancing the synthesis of this particular class of nanomaterials in the primary focus of this thesis. Chapter 1 presents studies of the synthesis of germanium sulfide, germanium selenide, and germanium telluride, using a hot-injection method. Both amorphous germanium selenide nanoparticles (NPs) and crystalline germanium telluride nanorods (NRs) were produced in this work. We founds that synthesis of GeSe and GeTe NPs at the smallest scales resulted in very poor quality product. Sensitivities like these may hinder progress in germanium chalcogenide nanocrystals synthesis. Chapter 2 demonstrates the preparation of Ag 2 S nanocrystals (NCs) from Cu 2-x S NCs by cation exchange. We show that during cation exchange, Ag content increased and Cu content decreased gradually. Simultaneously, the crystal phase changed from hexagonal Cu2-XS to rhombic Ag 2 S, accompanied by gradual damping and red shifting of the localized surface plasmon resonance (LSPR) absorbance of the NCs. This approach provides a valuable alternative means to synthesize Ag 2 S NPs using Cu 2-X S NPs as a template and demonstrated the viability of LSPR as a monitor for cation exchange.