Camadas de transporte de buracos depositados por magnetron sputtering
Carregando...
Arquivos
Data
2023-11-30
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Filmes de óxido de níquel tem sido estudado para o emprego de camada de transporte de buracos em células solares em perovskita, porque esse material apresenta boa estabilidade química e pode ser encontrado em abundância na natureza. No presente estudo, os filmes foram depositados pela técnica de Magnetron Sputtering utilizando uma fonte pulsada e uma fonte de radiofrequência. Os filmes de NiOx foram depositados sobre um filme de AZO, material atóxico e baixo custo. Foram investigadas as características de composições químicas, estruturais e óticas sob o efeito da variação da largura do pulso e potência do plasma, com ondas quadradas negativas e frequências de 1,0 e 1,37kHz para fonte pulsada e 13,7MHz para fonte de radiofrequência. Os filmes foram produzidos em uma câmara com pressões que variaram de 3,0 mTorr a 12mTorr. Para a ativação do plasma, utilizou-se um transformador de 1500 VA e 600V, junto com um variador de tensão monofásico de 1,5 kVA/220V. Foram utilizadas as técnica de espectroscopia de raios-X por dispersão de energia (EDS) para obter a composição química dos filmes de NiOx junto a microscopia de varredura eletrônica (MEV) para examinar a morfologia dos filmes. Para a análise de cristalinidade dos filmes, foi empregada a técnica de difração de raios-X. As propriedades ópticas dos filmes foram obtidas utilizando um espectrômetro UV-Vis-NIR (200nm a 2500nm), os filmes depositados com menores larguras de pulsos e baixas potências, alcançaram altos percentuais de transmitâncias na região do infravermelho próximo. Com os dados de transmitância e refletância foram calculadas as energias de gap ótico que variou de 2,85 a 3,58 eV, também foi investigada a energia de Urbach, e observou-se a variação de 206,3 a 901,2 meV, essas características são cruciais para escolha de matérias para construção de células fotovoltaicas.
Nickel oxide films have been the subject of extensive research for their potential utilization as hole transport layers in perovskite solar cells. This material is favored due to its robust chemical stability and abundant availability in the natural environment. In this investigation, the films were fabricated using the magnetron sputtering pulsed and radiofrequency sources. The NiOx films were deposited onto a substrate comprised of AZO (aluminum-doped zinc oxide), a cost-effective and non-toxic material. A comprehensive examination encompassed the evaluation of chemical composition, structural properties, and optical characteristics as a function of the pulse width and plasma power. For this purpose, square waveforms with frequencies of 1.0 and 1.37 kHz were employed for the pulsed source, and a frequency of 13.7 MHz for the radiofrequency source. Film production transpired within a chamber with pressure variations ranging from 3 to 12mTorr. Plasma activation was achieved through the utilization of a 1500 VA, 600V transformer, in conjunction with a 1.5 kVA/220V single-phase voltage inverter. Compositional analysis of the NiOx films was conducted through Energy Dispersive X-ray Spectroscopy (EDS), complemented by Scanning Electron Microscopy (SEM) to explore film morphology. To assess the crystallinity of the films, X-ray Diffraction (XRD) was employed. Optical properties were measured using a UV-Vis-NIR spectrometer, spanning a range from 200 nm to 2500 nm. Notably, films deposited with reduced pulse widths and low powers exhibited elevated transmittance percentages within the near-infrared spectrum. Based on transmittance and reflectance data, optical bandgap energies were computed, spanning from 2,85 to 3.58 eV. Furthermore, the Urbach energy was scrutinized, revealing a range from 206,3 to 901,2 meV. These characteristics play a pivotal role in the material selection process for the construction of photovoltaic cells.
Nickel oxide films have been the subject of extensive research for their potential utilization as hole transport layers in perovskite solar cells. This material is favored due to its robust chemical stability and abundant availability in the natural environment. In this investigation, the films were fabricated using the magnetron sputtering pulsed and radiofrequency sources. The NiOx films were deposited onto a substrate comprised of AZO (aluminum-doped zinc oxide), a cost-effective and non-toxic material. A comprehensive examination encompassed the evaluation of chemical composition, structural properties, and optical characteristics as a function of the pulse width and plasma power. For this purpose, square waveforms with frequencies of 1.0 and 1.37 kHz were employed for the pulsed source, and a frequency of 13.7 MHz for the radiofrequency source. Film production transpired within a chamber with pressure variations ranging from 3 to 12mTorr. Plasma activation was achieved through the utilization of a 1500 VA, 600V transformer, in conjunction with a 1.5 kVA/220V single-phase voltage inverter. Compositional analysis of the NiOx films was conducted through Energy Dispersive X-ray Spectroscopy (EDS), complemented by Scanning Electron Microscopy (SEM) to explore film morphology. To assess the crystallinity of the films, X-ray Diffraction (XRD) was employed. Optical properties were measured using a UV-Vis-NIR spectrometer, spanning a range from 200 nm to 2500 nm. Notably, films deposited with reduced pulse widths and low powers exhibited elevated transmittance percentages within the near-infrared spectrum. Based on transmittance and reflectance data, optical bandgap energies were computed, spanning from 2,85 to 3.58 eV. Furthermore, the Urbach energy was scrutinized, revealing a range from 206,3 to 901,2 meV. These characteristics play a pivotal role in the material selection process for the construction of photovoltaic cells.
Descrição
Palavras-chave
Óxido de Níquel, Propriedade óticas, Energia de band gap, Aluminum-doped zinc oxide, AZO, Band gap energy, Magnetron Sputtering, Nickel oxide, Optical properties
Como citar
GALINDO, F. O. Camadas de transporte de buracos depositados por magnetron sputtering. Orientador: Steven Frederick Durrant. 2023. 101 p. Dissertação (Mestrado em Ciência e Tecnologia de Materiais) – Instituto de Ciência e Tecnologia, Universidade Estadual Paulista, Sorocaba, 2023.