Polaronic Charge Separation in Mixed-Halide MX Solids.
Abstract
We have obtained clear evidence for photoinduced electron hole pair separation in mixed-halide, halogen-bridged transition metal (MX) chain solids. Resonance Raman experiments on doped and photoexcited single crystals of mixed-halide (M = Pt, X=Cl, Br, I) complexes indicate charge separation: electron polarons preferentially locate on the PtBr segment while hole polarons are trapped within PtCl segments. This polaron selectivity, which is potentially very useful for photovoltaic device applications, is demonstrated within theoretical calculations based on a discrete, 3/4-filled, two-band, tight-binding, extended Peierls-Hubbard model, showing strong hybridization of PtCl and PtBr electronic bands as the driving force for separation. In contrast to PtCl(/)x/Brl1-x25 the PtCl(/)/xI1-x system exhibits qualitatively different behavior such as 'self doping'.... Photoinduced electron, Polaron selectivity
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1993
- Accession Number
- ADA266073
Entities
People
- A. R. Bishop
- Akrati Saxena
- J. T. Gammel
- X. Z. Huang
Organizations
- Naval Command, Control and Ocean Surveillance Center