Publicação
Dielectric materials as new approach for Cu(In,Ga)Se2 front passivation
| Resumo: | The copper-indium-gallium-diselenide photovoltaic cell, also known as CIGS, achieves relatively high efficiencies while reducing the amount of material usage compared to standard silicon cells. To minimise its still occurring optoelectronic losses, the use passivation layers is a very promising strategy. Nonetheless, it is not yet fully understood the best architecture to adopt or how the passivation layers affect the remain layers of the cell. Two major chemical interface studies were conducted to understand the passivated interfaces based on: i) rear alumina passivation scheme with gold nanoparticle aggregates, and ii) front alumina passivation architecture schemes. These studies were performed with X-ray and Auger photoelectron spectroscopies, as these techniques are adequate to study surfaces with high enough sensitivity and are compatible with depth profile studies. This experimental work was developed at the International Iberian Nanotechnology Laboratory for the Nanofabrication for Optoelectronic Applications team. For the rear passivation study, it was verified that an alumina layer, acting simultaneously as a diffusion barrier for nanoparticle aggregates and as a rear passivation layer, enhanced the optical path in a CIGS photovoltaic cell. This was verified by the increase of the short circuit current density value compared to a conventional device. For the front passivation study, it was verified for the first time that a front passivation 5 nm layer of alumina could not resist the typical deposition process of the buffer layer of the CIGS photovoltaic cell. Future research should be considered regarding innovative architectures with nanoparticle aggregates. In addition, because alumina does not appear to alter the CIGS chemistry, alternative buffer layers for CIGS cells ought to be considered, or the compatibility of other dielectrics for front passivation with the remaining layers’ typical deposition processes must be investigated. |
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| Autores principais: | Monteiro, Margarida Marques Mano Coelho |
| Assunto: | CIGS passivation alumina Photoelectron Spectroscopy |
| Ano: | 2021 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade Nova de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório Institucional da UNL |
| Resumo: | The copper-indium-gallium-diselenide photovoltaic cell, also known as CIGS, achieves relatively high efficiencies while reducing the amount of material usage compared to standard silicon cells. To minimise its still occurring optoelectronic losses, the use passivation layers is a very promising strategy. Nonetheless, it is not yet fully understood the best architecture to adopt or how the passivation layers affect the remain layers of the cell. Two major chemical interface studies were conducted to understand the passivated interfaces based on: i) rear alumina passivation scheme with gold nanoparticle aggregates, and ii) front alumina passivation architecture schemes. These studies were performed with X-ray and Auger photoelectron spectroscopies, as these techniques are adequate to study surfaces with high enough sensitivity and are compatible with depth profile studies. This experimental work was developed at the International Iberian Nanotechnology Laboratory for the Nanofabrication for Optoelectronic Applications team. For the rear passivation study, it was verified that an alumina layer, acting simultaneously as a diffusion barrier for nanoparticle aggregates and as a rear passivation layer, enhanced the optical path in a CIGS photovoltaic cell. This was verified by the increase of the short circuit current density value compared to a conventional device. For the front passivation study, it was verified for the first time that a front passivation 5 nm layer of alumina could not resist the typical deposition process of the buffer layer of the CIGS photovoltaic cell. Future research should be considered regarding innovative architectures with nanoparticle aggregates. In addition, because alumina does not appear to alter the CIGS chemistry, alternative buffer layers for CIGS cells ought to be considered, or the compatibility of other dielectrics for front passivation with the remaining layers’ typical deposition processes must be investigated. |
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