Defect Control Of CuInSe₂ Quantum Dots And Their Photovoltaic Performance

Environmentally-friendly energy is increasingly value dagainst the background of the current environment pollution and energy deficiency.Among them,solar energy is a green and environmentally friendly energy source,and it is a better way to use solar energy as a substitute for the main energy source.As the application of solar cells developing rapidly,the lastest development is third generation that Quantum dots sensitized solar cells.In today's luminescent neighborhood materials,quantum dots play the important role due to the own characteristics.Although the ternary quantum dots have the own advantage,they also have the limitations,so the preparation and application of core-shell quantum dots have been studied by more and more researchers.This thesis mainly studies the preparation of core-shell quantum dots with good optical properties and high stability through a simple environmentally-friendly synthesis method.The prepared core-shell quantum dots are doped to improve the optical performance and stability.It is assembled into a quantum dot-sensitized solar cell and its performance is tested.The main contents are as follows:?1?Synthesis and application of Cu In Se₂/Zn Se quantum dotsThrough the exploration of the core-shell quantum dot synthesis method,then the exploration of the reaction process during the synthesis process,with the precursor is injected into the core-shell quantum dot reaction at a lower temperature.The thesis explored the core-shell quantum dots synthesized under different temperature conditions and their characterizations,so that a simple and green reaction was obtained.From the characterization results,the synthesized Cu In Se₂/Zn Se quantum dots and Cu In Se₂ quantum dots have a tetragonal phase,and the crystal plane structure is consistent.The fluorescence emission of the core-shell quantum dots is shifted,the fluorescence intensity is enhanced,and the fluorescence lifetime is extended.And as a photosensitizer,it was assembled into a quantum dot-sensitized solar cell.The measured cell efficiency was 5.55%.?2?Synthesis and application of Zn/Ag-Cu In Se₂quantum dotsThe synthesis of doped quantum dots by high temperature reaction method is obtained by doping different content of Zn to obtain Zn Cu In Se₂ quantum dots with different ratio of Cu/Zn.Through characterization analysis,it was found that XRD of doped quantum dots with different reaction temperatures and different reaction ratios shifted the diffraction peaks,the fluorescence position shifted,and the fluorescence intensity changed,so that the optimal synthesis scheme was obtained and assembled into a quantum dot sensitized solar cell,the measured Zn-Cu In Se₂ quantum dot sensitized solar cell efficiency was5.25%,and the Ag-Cu In Se₂ quantum dot sensitized solar cell efficiency reached 4.38%.?3?Synthesis and application of Zn-Cu In Se₂/Zn Se quantum dotsBy exploring the first two topics,we want to make the quality of quantum dot synthesis higher and more stable.Further,a method of synthesizing Cu In Se₂ quantum dots with zinc to make them into nuclear quantum dots,and then forming a Zn Se shell layer on the surface to explore.After preliminary exploration,the synthesized quantum dots were applied to solar cells and achieved a cell efficiency of 4.22%.