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Chirvony, Vladimir S.; Sekerbayed, Kairolla S.; Pérez-del-Rey, Daniel; Martínez Pastor, Juan Pascual; Palazón Huet, Francisco; Boix, Pablo P.
Perfil; Taurbayev, Toktar I.; Sessolo, Michele
Perfil; Bolink, Henk
Perfil |
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This document is a artículoDate2019
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It is widely accepted that a long photoluminescence (PL) lifetime in metal halide perovskite
films is a crucial and favorable factor, as it ensures a large charge diffusion length leading to a high power
conversion efficiency (PCE) in solar cells. It has been recently found that vacuumevaporated CH3NH3PbI3
(eMAPI) films show very short PL lifetimes of several nanoseconds. The corresponding solar cells,
however, have high photovoltage (>1.1 V) and PCEs (up to 20%). We rationalize this apparent
contradiction and show that eMAPI films are characterized by a very high diffusion coefficient D,
estimated from modeling the PL kinetics to exceed 1 cm2/s. Such high D values are favorable for long
diffusion length as well as fast transport of carriers to film surfaces, where they recombine nonradiatively
with surface recombination velocity S ∼ 104 cm/s. Possible physical origins leading to the high D values
are also discussed
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It is widely accepted that a long photoluminescence (PL) lifetime in metal halide perovskite
films is a crucial and favorable factor, as it ensures a large charge diffusion length leading to a high power
conversion efficiency (PCE) in solar cells. It has been recently found that vacuumevaporated CH3NH3PbI3
(eMAPI) films show very short PL lifetimes of several nanoseconds. The corresponding solar cells,
however, have high photovoltage (>1.1 V) and PCEs (up to 20%). We rationalize this apparent
contradiction and show that eMAPI films are characterized by a very high diffusion coefficient D,
estimated from modeling the PL kinetics to exceed 1 cm2/s. Such high D values are favorable for long
diffusion length as well as fast transport of carriers to film surfaces, where they recombine nonradiatively
with surface recombination velocity S ∼ 104 cm/s. Possible physical origins leading to the high D values
are also discussed
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Ver en el catálogo Trobes
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https://doi.org/10.1021/acs.jpclett.9b02329
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