Document Type

Article

Original Publication Date

2016

Journal/Book/Conference Title

Nanoscale

Volume

8

Issue

41

First Page

17836

Last Page

17842

DOI of Original Publication

10.1039/c6nr05573g

Comments

Originally published at http://doi.org/10.1039/c6nr05573g.

Date of Submission

January 2017

Abstract

Organic-inorganic hybrid perovskites, well known for their potential as the next generation solar cells, have found another niche application in optoelectronics. This was demonstrated in a recent experiment (L. Dou, et al., Science, 2015, 349, 1518) on atomically thin (C4H9NH3)(2)PbBr4, where, due to quantum confinement, the bandgap and the exciton binding energy are enhanced over their corresponding values in the three-dimensional bulk phase. Using density functional theory we show that when halogen atoms (e.g. I) are sequentially replaced with superhalogen molecules (e.g. BH4) the bandgap and exciton binding energy increase monotonically with the superhalogen content with the exciton binding energy of (C4H9NH3)(2)Pb(BH4)(4) approaching the value in monolayer black phosphorus. Lead-free admixtures (C4H9NH3)(2)MI4-x(BH4)(x) (M = Sn and Ge; x = 0-4) also show a similar trend. Thus, a combination of quantum confinement and compositional change can be used as an effective strategy to tailor the bandgap and the exciton binding energy of two-dimensional hybrid perovskites, making them promising candidates for optoelectronic applications.

Rights

© The Royal Society of Chemistry 2016

Is Part Of

VCU Physics Publications

c6nr05573g1.pdf (1532 kB)

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