Synthesis and characterization of indium phosphide quantum dots for photoelectrochemical applications
- Autores: Imen Harabi
- Directores de la Tesis: Hanae Toura (dir. tes.), Bernabé Marí Soucase (dir. tes.)
- Lectura: En la Universitat Politècnica de València ( España ) en 2023
- Idioma: inglés
- Tribunal Calificador de la Tesis: Juan Antonio García Manrique (presid.), Abdelhakim Nafidi (secret.), Asmae Arbaoui (voc.)
- Programa de doctorado: Programa de Doctorado en Diseño, Fabricación y Gestión de Proyectos Industriales por la Universitat Politècnica de València
- Materias:
- Enlaces
- Tesis en acceso abierto en: RiuNet
- Resumen
Today, there are modern technological and engineering challenges that would advantage from the contributions of the nanoscience community and nanotechnology. At this scale, the physical and chemical properties of the systems are highly dependent on respect for the environment (energy saving, pollution minimization, global warming etc). In this term, nanoparticles based on II-VI semiconductors "Quantum Dots" have been by far the most studied. Among several material, InP Quantum Dots has brought huge interest because of the low toxicity features. This promising element is the subject of this thesis. Hence, to obtain monodisperse particles in solution, the hot injection route has several advantages that make it a useful technique, such as controlling the size of the nanoparticles.
This work deals with the synthesis of InP Quantum Dot by hot injection method as the basis for photoelectrochemical application.
We started our work by optimizing the synthesis of InP QDs by the hot injection method while studying the synthesis parameters on the morphological, structural, and specially the photoluminescence properties of InP Quantum Dots.
Initially, the optimization of the Quantum Dots conditions was based on the enhancement the optical properties in particular the photoluminescence. When we passivated the InP QDs by ZnS shell, ZnS/ZnS double shell we succeed to decrease the surface defects resulting on the enhancement of the InP QDs photoluminescence. Also, the surface morphology of these QDs has a more regular spherical form and is well dispersed. On the other hand, the optical properties of the InP QDs doped with Vanadium was shown no improvement in the photoluminescence while there's a decrease on the size of the nanoparticle.
The second aim of this thesis revolves around InP QDs deposited on metallic titanium dioxide nanotubes TiO2 by spin coating method with a view to comparing the photoelectrochemical efficiency of core InP QDs, core/shell InP/ZnS QDs, and core/shell/shell InP/ZnS/ZnS QDs. This study shows an increase in the photocurrent almost 4 and 6 times higher than TiO2/InP QDs. Hence, this measurement aims to observe the dynamic behavior of the material and to assess whether the charges recombine rapidly into the TiO2 NTAs Nanotubes from the quantum dots. So, a good efficiency in the photocurrent response was obtained following the growth core/shell/shell system due to the successful passivation of non-radiative recombination sites such as surface trap states.
This result was supported by a simulation study of the different parameters characterizes the solar cell based TiO2/InP, TiO2/InP/ZnS and TiO2/InP/ZnS/ZnS with software SCAPS-1D. According to this theoretical work, a good performance of the cell has obtained in the adding of ZnS layer. The simulation results show that the InP was able to successfully utilize the full spectrum of light when coated with ZnS layer on top.
