Ⅰ. Introduction 1 1.1 Solar Cells for Renewable Energy Harvesting 1 1.2 Emergence of the Colloidal Quantum Dot Solar Cells 1 1.3 Lead Sulfide Colloidal Quantum Dot Solar Cells 2 1.4 Limited Photovoltaic Performance Derived from Incomplete Surface Chemistry of the PbS QD 2 1.5 PbS QD Film Annealing Process 3 1.6 Recent Research Trend of Short-Time Annealing on the PbS QD Film 3 1.7 New Approach Method using FLA in the PbS CQDSCs 4 Ⅱ. Experimental 5 2.1 Synthesis of OA-capped PbS Colloidal Quantum Dot 5 2.2 Ligand Exchange Step for CQD Ink 5 2.3 CQD Solar Cell Device Fabrication 6 2.4 Device Characterization of PbS CQD 7 2.5 Solar Cell Measurement 7 Ⅲ. Results and discussion 8 3.1 The Formation of Pb-OH and Pb-O Species on the PbS QD Films 8 3.2 The HA and FLA Annealing Process and Optimization of Annealing Conditions 8 3.2.1 Process of the HA and FLA Treatments 8 3.2.2 Optimization of the Energy Density through the PCE and Film Contraction 11 3.3 The Analysis of the Effect of the Hydroxylation and Oxidation on the PbS QD Sur-face 14 3.4 Electrical Properties of the PbS QD Films 16 3.5 Solar Cell Structure and Performance 20 Ⅳ. Conclusion 26 Ⅴ. Reference 27 VI. 요약문 30