Co-Adsorbent Effect on the Sensitization of TiO2 and ZnO Surfaces: A Theoretical Study

Risplendi, Francesca; Cicero, Giancarlo

doi:10.1021/acs.jpcc.5b11113

PORTO @ Archivio Istituzionale della Ricerca

IRIS è la soluzione IT che facilita la raccolta e la gestione dei dati relativi alle attività e ai prodotti della ricerca. Fornisce a ricercatori, amministratori e valutatori gli strumenti per monitorare i risultati della ricerca, aumentarne la visibilità e allocare in modo efficace le risorse disponibili.

Co-adsorbents are often employed in DSSC to avoid electron/ hole recombination at the hybrid organic/inorganic interface. Here we investigate, by means of density functional theory simulations, the changes induced in the structural and electronic properties of a hybrid heterostructure by the presence of a co-adsorbent. In particular, we focus on a prototype interface obtained by co-grafting a dye molecule (the hemi-squaraine dye) and imidazole at the oxide surfaces mostly employed in DSSC (anatase-TiO2(101) and ZnO(1100)). Our results show that beside avoiding dye aggregation, the co- adsorbent plays an active role in stabilizing the binding between the chromophore and oxide substrate and in tuning the optoelectronic properties of the system. We found that imidazole shifts downward the dye energy levels (HOMO and LUMO) while raising the oxide valence and conduction bands, strongly influencing the energy alignment of the interface. As such, a co-adsorbent can either modify the type of heterostructure (straddling, staggered, or broken gap) or change the open circuit voltage (Voc), with potentially both beneficial or detrimental effect of the final device performance.

Titolo:	Co-Adsorbent Effect on the Sensitization of TiO2 and ZnO Surfaces: A Theoretical Study
Autori:	RISPLENDI, FRANCESCA CICERO, GIANCARLO
Data di pubblicazione:	2015
Rivista:	JOURNAL OF PHYSICAL CHEMISTRY. C.
Digital Object Identifier (DOI):	http://dx.doi.org/10.1021/acs.jpcc.5b11113
Appare nelle tipologie:	1.1 Articolo in rivista

File in questo prodotto:

File	Descrizione	Tipologia	Licenza
2015_JPCC_coadsorbent.pdf	Articolo principale	2. Post-print / Author's Accepted Manuscript	Non Pubblico - Accesso privato/ristretto	Administrator Richiedi una copia

Utilizza questo identificativo per citare o creare un link a questo documento:
http://hdl.handle.net/11583/2625715

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.