Atomistic Origins of High-Performance in Hybrid Halide Perovskite Solar Cells

TY - JOUR

T1 - Atomistic Origins of High-Performance in Hybrid Halide Perovskite Solar Cells

AU - Frost, Jarvist M.

AU - Butler, Keith T.

AU - Brivio, Federico

AU - Hendon, Christopher H.

AU - van Schilfgaarde, Mark

AU - Walsh, Aron

PY - 2014/5/14

Y1 - 2014/5/14

N2 - The performance of organometallic perovskite solar cells has rapidly surpassed that of both conventional dye-sensitized and organic photovoltaics. High-power conversion efficiency can be realized in both mesoporous and thin-film device architectures. We address the origin of this success in the context of the materials chemistry and physics of the bulk perovskite as described by electronic structure calculations. In addition to the basic optoelectronic properties essential for an efficient photovoltaic device (spectrally suitable band gap, high optical absorption, low carrier effective masses), the materials are structurally and compositionally flexible. As we show, hybrid perovskites exhibit spontaneous electric polarization; we also suggest ways in which this can be tuned through judicious choice of the organic cation. The presence of ferroelectric domains will result in internal junctions that may aid separation of photoexcited electron and hole pairs, and reduction of recombination through segregation of charge carriers. The combination of high dielectric constant and low effective mass promotes both Wannier-Mott exciton separation and effective ionization of donor and acceptor defects. The photoferroic effect could be exploited in nanostructured films to generate a higher open circuit voltage and may contribute to the current-voltage hysteresis observed in perovskite solar cells.

AB - The performance of organometallic perovskite solar cells has rapidly surpassed that of both conventional dye-sensitized and organic photovoltaics. High-power conversion efficiency can be realized in both mesoporous and thin-film device architectures. We address the origin of this success in the context of the materials chemistry and physics of the bulk perovskite as described by electronic structure calculations. In addition to the basic optoelectronic properties essential for an efficient photovoltaic device (spectrally suitable band gap, high optical absorption, low carrier effective masses), the materials are structurally and compositionally flexible. As we show, hybrid perovskites exhibit spontaneous electric polarization; we also suggest ways in which this can be tuned through judicious choice of the organic cation. The presence of ferroelectric domains will result in internal junctions that may aid separation of photoexcited electron and hole pairs, and reduction of recombination through segregation of charge carriers. The combination of high dielectric constant and low effective mass promotes both Wannier-Mott exciton separation and effective ionization of donor and acceptor defects. The photoferroic effect could be exploited in nanostructured films to generate a higher open circuit voltage and may contribute to the current-voltage hysteresis observed in perovskite solar cells.

KW - Hybrid perovskite

KW - photovoltaic

KW - density functional theory

KW - ferroelectric

KW - METAL-OXIDES

KW - LEAD IODIDE

KW - PHOTOVOLTAIC CELLS

KW - PHASE-TRANSITIONS

KW - CH3NH3 PBI3

KW - THIN-FILMS

KW - POLARIZATION

KW - ELECTRON

KW - TRANSPORT

KW - TRIHALIDE

U2 - 10.1021/nl500390f

DO - 10.1021/nl500390f

M3 - Article

SN - 1530-6984

VL - 14

SP - 2584

EP - 2590

JO - Nano Letters

JF - Nano Letters

IS - 5

ER -