Cs deposition on c-axis-oriented thin films of α-(BEDT-TTF)2I3: evidence for electron doping and intercalation

Abstract

The deposition of Cs on c-axis-oriented thin films of α-(BEDT-TTF)2I3 causes a shift of the chemical potential in agreement with addition of electrons to the system. At high Cs doses a chemical reaction between Cs+ and I3- occurs, with the formation of CsI and probably mainly I2. In the valence-band regime new structures appear, due to I- ,i.e, CsI, and molecular orbitals of I2 derived from I 5p. The hybridization between these orbitals and the BEDT-TTF orbitals is negligible. The remarkable changes in the I 4d spectrum caused by Cs deposition can be understood within the framework of the proposed chemical reaction.