000199008 001__ 199008
000199008 005__ 20181203023510.0
000199008 0247_ $$2doi$$a10.1039/c4cp00294f
000199008 022__ $$a1463-9076
000199008 02470 $$2ISI$$a000335015700048
000199008 037__ $$aARTICLE
000199008 245__ $$aQuantum dot-sensitized solar cells based on directly adsorbed zinc copper indium sulfide colloids
000199008 260__ $$aCambridge$$bRoyal Soc Chemistry$$c2014
000199008 269__ $$a2014
000199008 300__ $$a8
000199008 336__ $$aJournal Articles
000199008 520__ $$aHeavy metal-based quantum dots (QDs) have been demonstrated to behave as efficient sensitizers in QD-sensitized solar cells (QDSSCs), as attested by the countless studies 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 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 subjected to the ZnS treatment. Its effects on electron recombination with the electrolyte are analyzed through electrochemical impedance spectroscopy and photo-potential measurements. The corresponding results bring out the role of the ZnS coating as a barrier layer in preventing electron leakage toward the electrolyte, as argued in other QD-sensitized systems. The beneficial effect of the ZnS coating is ultimately reflected in 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.
000199008 700__ $$aGuijarro, Nestor
000199008 700__ $$aGuillen, Elena
000199008 700__ $$aLana-Villarreal, Teresa
000199008 700__ $$aGomez, Roberto
000199008 773__ $$j16$$k19$$q9115-9122$$tPhysical Chemistry Chemical Physics
000199008 909C0 $$0252439$$pISIC$$xU10095
000199008 909CO $$ooai:infoscience.tind.io:199008$$pSB$$particle
000199008 937__ $$aEPFL-ARTICLE-199008
000199008 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED
000199008 980__ $$aARTICLE