Evidence for long drift carrier lifetimes in [Fe(Htrz)2(trz)](BF4) plus polyaniline composites

Abstract

An effort has been made to determine the majority carrier and drift carrier lifetimes in the promising spin crossover molecule [Fe(Htrz) 2 (trz)](BF 4 ) (where Htrz = 1H-1,2,4-triazole) plus polyaniline composite. The current voltage and capacitance voltage characteristics of the [Fe(Htrz) 2 (trz)](BF 4 ) plus polyaniline composite were studied at both the low spin state at T = 320 K and the high spin state at T = 380 K. In these composites, the drift carrier lifetimes are in excess of microseconds, and there are indications that the majority carriers are holes. While the drift carrier lifetime is much lower when the [Fe(Htrz) 2 (trz)](BF 4 ) plus polyaniline composite is in the low spin state, there are indications that for at least one polyaniline composite, the carrier mobility is much higher in the low spin state so that the mobility is consistent with the higher conductivity of the low spin state. • Very long carrier lifetime measured in spin crossover system. • Impressive mobility changes. • Transistors can be made of [Fe(Htrz) 2 (trz)](BF 4 ) plus polyaniline. • Comparison of conductance in low and high spin state.