CdSe Quantum Dot Sensitized Solar Cells. Shuttling Electrons Through Stacked Carbon Nanocups

Abstract

The charge separation between excited CdSe semiconductor quantum dots and stacked-cup carbon nanotubes (SCCNTs) has been successfully tapped to generate photocurrent in a quantum dot sensitized solar cell (QDSC). By employing an electrophoretic deposition technique we have cast SCCNT-CdSe composite films on optically transparent electrodes (OTEs). The quenching of CdSe emission, as well as transient absorption measurements, confirms ultrafast electron transfer to SCCNTs. The rate constant for electron transfer increases from 9.51 x 10(9) s(-1) to 7.04 x 10(10) s(-1) as we decrease the size of CdSe nanoparticles from 4.5 to 3 nm. The ability of SCCNTs to collect and transport electrons from excited CdSe has been established from photocurrent measurements. The morphological and excited state properties of SCCNT-CdSe composites demonstrate their usefulness in energy conversion devices.

Células solares sensibilizadas por pontos quânticos

“…A primeira vez que NTC foram utilizados como material sensibilizador data de 2005, quando Sheeney-Haj-Khia e colaboradores suportaram, em um eletrodo de ouro, nanotubos modificados com pontos quânticos de CdS. 110 Um esquema parecido foi desenvolvido por Kamat e colaboradores, 111 que com o auxílio da técnica de eletroforese depositaram o material de NTC/CdSe em um substrato altamente condutivo. Na interação do estado excitado entre CdSe e NTC observou-se um aumento na transferência de elétrons.…”

“…124 Em 2003, Zeng e colaboradores descreveram uma célula solar sólida, utilizando pontos quânticos de InP obtidos via coloidal, com o objetivo de mostrar os benefícios práticos adquiridos com este dispositivo, bem como uma possível melhoria na quantização e consequentemente na eficiência obtida. 125 Em 2012, Barceló e sua equipe apresentaram a primeira montagem da célula solar sólida utilizando pontos quânticos de CdSe obtidos pelo método SILAR e como HTM um semicondutor orgânico do tipo p, alcançando valores consideráveis de potencial. 126 Entretanto, o valor de eficiência obtido ainda se encontra longe do desejado, aproximadamente 0,34%, evidenciando assim a necessidade de mais estudos na configuração deste dispositivo fotovoltaico.…”

ZnO anchored graphene hydrophobic nanocomposite-based bulk heterojunction solar cells showing enhanced short-circuit current

“…22,23 Lots of work has already been conducted on CNTs, even regarding their application in PV, but not much has happened specically for advancement in terms of efficiency and decrement in terms of cost. 27 and ne electron acceptor, is extremely important and even less expensive when synthesized on a large scale in comparison to CNTs.…”

Integration of surface science, nanoscience, and catalysis

“…Oil refining relies on chemical reactions at interfaces of gas feedstock and various catalysts. New energy conversion processes extensively involve heterogeneous catalysis such as (1) evolution of H 2 and O 2 on the surfaces of cocatalysts in solar-driven water-splitting [29][30][31][32][33][34], and (2) generation of electricity from oxidation of fuel molecules on the surface of the electrode in fuel cells [35][36][37]. Most of the issues in environmental science involve the chemical process occurring on the surface of various materials such as minerals under ambient conditions [38][39][40].…”