Quantum Dot-Sensitized Solar Cells Based on Directly Adsorbed Zinc Copper Indium Sulfide Colloids


Autoria(s): Guijarro Carratalá, Néstor; Guillén Rodríguez, Elena; Lana Villarreal, Teresa; Gómez, Roberto
Contribuinte(s)

Universidad de Alicante. Departamento de Química Física

Universidad de Alicante. Instituto Universitario de Electroquímica

Grupo de Fotoquímica y Electroquímica de Semiconductores (GFES)

Data(s)

03/04/2014

03/04/2014

26/03/2014

Resumo

Heavy metal-based quantum dots (QDs) have demonstrated to behave as efficient sensitizers in QD-sensitized solar cells (QDSSCs), as attested by the countless works and encouraging efficiencies reported so far. However, their intrinsic toxicity has arisen as a major issue for the prospects of commercialization. Here, we examine the potential of environmentally friendly zinc copper indium sulfide (ZCIS) QDs for the fabrication of liquid-junction QDSSCs by means of photoelectrochemical measurements. A straightforward approach to directly adsorb ZCIS QDs on TiO2 from a colloidal dispersion is presented. Incident photon-to-current efficiency (IPCE) spectra of sensitized photoanodes show a marked dependence on the adsorption time, with longer times leading to poorer performances. Cyclic voltammograms point to a blockage of the channels of the mesoporous TiO2 film by the agglomeration of QDs as the main reason for the decrease in efficiency. Photoanodes were also submitted to the ZnS treatment. Its effects on electron recombination with the electrolyte are analyzed through electrochemical impedance spectroscopy and photopotential measurements. The corresponding results bring out the role of the ZnS coating as a barrier layer preventing electron leakage toward the electrolyte, as argued in other QD-sensitized systems. The beneficial effect of the ZnS coating is ultimately reflected on the power conversion efficiency of complete devices, reaching values of 2 %. In a more general vein, through these findings, we aim to call the attention to the potentiality of this quaternary alloy, virtually unexplored as a light harvester for sensitized devices.

N.G. is grateful to the Spanish Ministry of Education for the award of an FPU grant. The group acknowledges support of the Spanish Ministry of Economy and Competitiveness through projects HOPE CSD2007-00007 (Consolider Ingenio 2010) and MAT2012-37676 (Fondos FEDER).

Identificador

Physical Chemistry Chemical Physics. 2014, 16: 9115-9122. doi:10.1039/C4CP00294F

1463-9076 (Print)

1463-9084 (Online)

http://hdl.handle.net/10045/36483

10.1039/C4CP00294F

Idioma(s)

eng

Publicador

Royal Society of Chemistry

Relação

http://dx.doi.org/10.1039/C4CP00294F

Direitos

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence

info:eu-repo/semantics/openAccess

Palavras-Chave #Quantum dots #Quantum dot-sensitized solar cells #Zinc copper indium sulfide #Colloids #Química Física
Tipo

info:eu-repo/semantics/article