Skip to Main content Skip to Navigation
New interface

Synthèse de nanocristaux de type Chalcopyrite en vue d'applications en cellules solaires

Abstract : This work is devoted to the study of ternary semiconductor nanocrystals, and their application inhybrid organic/inorganic solar cells. Semiconductor nanocrystals absorb light at controlled wavelength(depending on their size and composition) and are able to transport charges. They form a colloidalsolution in organic solvent compatible with low-cost deposition in thin films. Nowadays, the bestefficiency for such hybrid solar cells is obtained with binary nanocrystals containing lead or cadmium.Ternary nanocrystals preserve the opticla and electronic properties of binary nanocrystals withoutrelying on toxic elements, but it is still a challenge to control their composition and structure.In this thesis, CuInS2 nanocrystals of controlled size and composition were syntesized. A study ofnucleation and growth was carried out by following the synthesis in situ with X-ray radiation at thesynchrotron. This has shown that precursors’ organize themselves into plans of atoms separated by twotimes the length of the ligand (here dodecanethiol, DDT). Ligands stabilize the nanocrystals in colloidalsolution, but their insulating character inhibits efficient charge transfer and transport. Ligand exchangewith ethylhexanethiol (EHT) improves the conductivity of thin films and changethe energetic level ofthe nanocrystals.We studied an approach of hybrid solar cell design, consisting in a bulk heterojunctionof two semiconductor organic components (P3HT and PCBM) and CuInS2 nanocrystals. The efficencyof the cells where nanocrystals are added are better than the one with only P3HT:PCBM. The chargetransfer and mobility was studied by the mean of light induced ESR and CELIV respectively. It hasshown that the improvement of the solar cell efficiency is mainly related to an improvement of thecharge generation and dissociation in the ternary blend.
Document type :
Complete list of metadata

Cited literature [183 references]  Display  Hide  Download
Contributor : ABES STAR :  Contact
Submitted on : Tuesday, September 9, 2014 - 1:28:12 PM
Last modification on : Wednesday, November 2, 2022 - 3:52:30 AM
Long-term archiving on: : Wednesday, December 10, 2014 - 12:08:42 PM


Version validated by the jury (STAR)


  • HAL Id : tel-01062176, version 1



Aurélie Lefrançois. Synthèse de nanocristaux de type Chalcopyrite en vue d'applications en cellules solaires. Autre. Université de Grenoble, 2013. Français. ⟨NNT : 2013GRENV067⟩. ⟨tel-01062176⟩



Record views


Files downloads