Small polaron effect on carrier recombination in perovskite manganite thin films

Wu, G.R.; Sasaki, Minoru; Isa, T.; Negishi, H.; Inoue, M.; Gao, Wenxiu; Xiong, Ge

doi:10.1016/s0038-1098(01)00117-x

Cited by 5 publications

(2 citation statements)

References 22 publications

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“…7 Combining the diffusion length L = √ τ D and the Einstein relation for the diffusion coefficient D = μk B T /e with the mobility μ = 0.015 cm 2 /Vs, typical for majority carriers in PCMO at room temperature (μ = 1/ρep with resistivity ρ = 0.1 cm and effective carrier density p = 4 × 10 21 cm −3 ), photocarrier lifetimes τ = 1-30 ns correspond to the estimated L = 5-35 nm. Wu et al report on photocarrier lifetimes of 500 ns in the roomtemperature small-polaron regime of La 0.6 Ca 0.4 MnO 3 thin films, 40 which points to strongly reduced mobilities of excess carriers, e.g., by localization at acceptor defects. 28 In future work, direct experimental access to these important questions of nanoscale carrier diffusion and recombination could be provided by high-resolution electronbeam-induced current measurements as demonstrated by Han et al 41…”

Section: Transport Properties Ii: Photovoltaic Effect and Photocarmentioning

confidence: 99%

Polaron absorption for photovoltaic energy conversion in a manganite-titanatepnheterojunction

Saucke¹,

Norpoth²,

Jooß³

et al. 2012

Phys. Rev. B

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The relation among structure, electric transport, and photovoltaic effect is investigated for a pn heterojunction with strong correlation interactions. A perovskite interface is chosen as a model system consisting of the p-doped strongly correlated manganite Pr 0.64 Ca 0.36 MnO 3 (PCMO) and the n-doped titanate SrTi 1−y Nb y O 3 (y = 0.002 and 0.01). High-resolution electron microscopy and spectroscopy reveal a nearly dislocation-free, epitaxial interface and give insight into the local atomic and electronic structure. The presence of a photovoltaic effect under visible light at room temperature suggests the existence of mobile excited polarons within the band-gapfree PCMO absorber. The temperature-dependent rectifying current-voltage characteristics prove to be mainly determined by the presence of an interfacial energy spike in the conduction band and are affected by the colossal electroresistance effect. From the comparison of photocurrents and spatiotemporal distributions of photogenerated carriers (deduced from optical absorption spectroscopy), we discuss the range of the excited polaron diffusion length.

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Section: Transport Properties Ii: Photovoltaic Effect and Photocarmentioning

confidence: 99%

Polaron absorption for photovoltaic energy conversion in a manganite-titanatepnheterojunction

Saucke¹,

Norpoth²,

Jooß³

et al. 2012

Phys. Rev. B

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show abstract

“…The metallic behaviour is usually described in terms of electron-phonon interaction, however the JT distortion also plays an important role in the high-temperature paramagnetic phase, where the carriers (electrons or holes) are localized as small polarons due to a strong JT distortion. Henceforth, polaronic hopping conduction mechanism is effective in describing the semiconducting behaviour above T C [4].…”

Section: Introductionmentioning

confidence: 99%