| Resumo: | The photoluminescence, transmittance, charge-carrier recombination dynamics, mobility, and diffusion length of CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf> are investigated in the temperature range from 8 to 370 K. Profound changes in the optoelectronic properties of this prototypical photovoltaic material are observed across the two structural phase transitions occurring at 160 and 310 K. Drude-like terahertz photoconductivity spectra at all temperatures above 80 K suggest that charge localization effects are absent in this range. The monomolecular charge-carrier recombination rate generally increases with rising temperature, indicating a mechanism dominated by ionized impurity mediated recombination. Deduced activation energies E<inf>a</inf> associated with ionization are found to increase markedly from the room-temperature tetragonal (E<inf>a</inf> ≈ 20 meV) to the higher-temperature cubic (E<inf>a</inf> ≈ 200 meV) phase adopted above 310 K. Conversely, the bimolecular rate constant decreases with rising temperature as charge-carrier mobility declines, while the Auger rate constant is highly phase specific, suggesting a strong dependence on electronic band structure. The charge-carrier diffusion length gradually decreases with rising temperature from about 3 μm at -93 °C to 1.2 μm at 67 °C but remains well above the optical absorption depth in the visible spectrum. These results demonstrate that there are no fundamental obstacles to the operation of cells based on CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf> under typical field conditions.
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