We performed density functional calculations aimed at identifying the atomistic and electronic structure origin of the valence and conduction band, and band gap tunability of halide perovskites ABX3 upon variations of the monovalent and bivalent cations A and B and the halide anion X. We found that the two key ingredients are the overlap between atomic orbitals of the bivalent cation and the halide anion, and the electronic charge on the metal center. In particular, lower gaps are associated with higher negative antibonding overlap of the states at the valence band maximum (VBM), and higher charge on the bivalent cation in the states at the conduction band minimum (CBM). Both VBM orbital overlap and CBM charge on the metal ion can be tuned over a wide range by changes in the chemical nature of A, B and X, as well as by variations of the crystal structure. On the basis of our results, we provide some practical rules to tune the valence band maximum, respectively the conduction band minimum, and thus the band gap in this class of materials.

Valence and conduction band tuning in halide perovskites for solar cell applications / Meloni, Simone; Palermo, Giulia; Ashari Astani, Negar; Grätzel, Michael; Rothlisberger, Ursula. - In: JOURNAL OF MATERIALS CHEMISTRY. A. - ISSN 2050-7488. - 4:41(2016), pp. 15997-16002. [10.1039/c6ta04949d]

Valence and conduction band tuning in halide perovskites for solar cell applications

MELONI, Simone;
2016

Abstract

We performed density functional calculations aimed at identifying the atomistic and electronic structure origin of the valence and conduction band, and band gap tunability of halide perovskites ABX3 upon variations of the monovalent and bivalent cations A and B and the halide anion X. We found that the two key ingredients are the overlap between atomic orbitals of the bivalent cation and the halide anion, and the electronic charge on the metal center. In particular, lower gaps are associated with higher negative antibonding overlap of the states at the valence band maximum (VBM), and higher charge on the bivalent cation in the states at the conduction band minimum (CBM). Both VBM orbital overlap and CBM charge on the metal ion can be tuned over a wide range by changes in the chemical nature of A, B and X, as well as by variations of the crystal structure. On the basis of our results, we provide some practical rules to tune the valence band maximum, respectively the conduction band minimum, and thus the band gap in this class of materials.
2016
chemistry; renewable energy; sustainability and the environment; materials science
01 Pubblicazione su rivista::01a Articolo in rivista
Valence and conduction band tuning in halide perovskites for solar cell applications / Meloni, Simone; Palermo, Giulia; Ashari Astani, Negar; Grätzel, Michael; Rothlisberger, Ursula. - In: JOURNAL OF MATERIALS CHEMISTRY. A. - ISSN 2050-7488. - 4:41(2016), pp. 15997-16002. [10.1039/c6ta04949d]
File allegati a questo prodotto
File Dimensione Formato  
Meloni_valence-and-conduction-band_2016 .pdf

solo gestori archivio

Tipologia: Versione editoriale (versione pubblicata con il layout dell'editore)
Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 555.18 kB
Formato Adobe PDF
555.18 kB Adobe PDF   Contatta l'autore

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

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/950985
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 128
  • ???jsp.display-item.citation.isi??? 120
social impact