Femto- to Microsecond Dynamics of Excited Electrons in a Quadruple Cation Perovskite

Abstract

Quadruple cation mixed halide perovskite, GA0.015Cs0.046MA0.152FA0.787Pb­(I0.815Br0.185)3, single crystals were grown for the first time using an inverse temperature crystallization process. Solar cell devices in n-i-p stack configuration using thin films of the same materials showed power conversion efficiency above 20%. Complementary time-resolved spectroscopy confirmed that polycrystalline thin films and single crystals identically composed exhibit similar carrier dynamics in the picosecond range. Cooling of excited carriers and bandgap renormalization occur on the same time scale of 200–300 fs. The radiative recombination coefficient (1.2 × 10–9 cm3/s) is comparable to values reported for a GaAs semiconductor. At low excitation density, a long carrier lifetime of 3.2 μs was recorded possibly due to the passivation of recombination centers. This study clarifies discrepancies about the lifetime of hot carriers, the impact of radiative recombination, and the role of recombination centers on solar cell performance. The quadruple cation perovskites displayed short time dynamics with slow recombination of charge carriers.

Recent Progress in Mixed A‐Site Cation Halide Perovskite Thin‐Films and Nanocrystals for Solar Cells and Light‐Emitting Diodes

“…The mixed A‐cation LHP NCs can be synthesized directly using the mixture of desired A‐cation precursors or by applying post‐synthetic A‐cation exchange and cross‐exchange on pre‐synthesized mono‐cation LHP NCs, as illustrated in Figure . The direct synthesis can be carried out by classical methods such as hot‐injection [ 48–175 ] or reprecipitation [ …”

From Structural Design to Functional Construction: Amine Molecules in High‐Performance Formamidinium‐Based Perovskite Solar Cells

“…When using Gua + for A‐site doping, lattice expansion can occur in the crystal unit (Figure 2b), [43] which compensates the original shrinkage of the CsFAMA perovskite and effectively inhibits the formation of lattice defects and trap states (Figure 2c). As a consequence, Gua + doping leads to reduced charge recombination, prolonged carrier lifetimes, and enlarged V oc values from 1.11 V to 1.19 V [44, 45] . Kim et al.…”

“…[41,42] When using Gua + for A-site doping, lattice expansion can occur in the crystal unit (Figure 2b), [43] which compensates the original shrinkage of the CsFAMA perovskite and effectively inhibits the formation of lattice defects and trap states (Figure 2c). As a consequence, Gua + doping leads to reduced charge recombination, prolonged carrier lifetimes, and enlarged V oc values from 1.11 V to 1.19 V. [44,45] Kim et al used the dual substitution of FA + sites by methylenediammonium (MDA 2 + , larger than FA + ) and Cs + (smaller than FA + ) to relax the lattice strain and stabilize α-FAPbI 3 (Figure 2d). [1] The lattice strain is relaxed to the greatest extent with 3 mol % MDA 2 + and Cs + (Figure 2e), thereby leading to a PSC with a certified efficiency of 24.4 %.…”

Toward stable lead halide perovskite solar cells: A knob on the A/X sites components

“…(2020) BA 2 MA 3 Pb 4 I 13 ITO/SnO 2 /PVSK/Spiro-OMeTAD/Au under continuous 1 sun, AM1.5G illumination Retains 90% of the original PCE after 1100 h 16.25 1.31 2020 Liang et al. (2021) GA 0.015 Cs 0.046 MA 0.152 FA 0.787 Pb(I 0.815 Br 0.185 ) 3 FTO/c-TiO 2 /Li-doped m-TiO 2 /PVSK/Spiro-OMeTAD/Au under illumination (AM1.5G 100 mW cm −2 ) Retains over 90% of the original PCE after 3000s at MPP 20.16 1.18 2020 Jung et al. (2020) Cs 0.5 FA 0.5 PbI 3 QDs ITO/SnO 2 /PVSK/Spiro-OMeTAD/Au at open circuit under 1 sun illumination in N 2 at 50–65°C Retains over 94% of the original PCE for 600 h 16.6 1.17 2020 Hao et al.…”