Impedance anisotropy and quantum photocapacity of bio/inorganic clathrates InSe〈histidine〉 and gase〈histidine〉

Abstract

Intercalated nanostructures of InSe〈histidine〉 and GaSe〈histidine〉 were formed. Phenomena of the negative capacitance and the quantum capacitance are visualized in the first nanostructure. The introduction of histidine between indium selenide layers leads to increasing of conductivity anisotropy ( σ|| σ⊥ ) from 67 to 226. Temperature dependences of the real component of the complex impedance indicate semiconductor mechanism of conductivity along nanolayers with two activation energies: 1.6 meV at low-temperature and 0.25 meV in high-temperature regions. Appearance of the giant high-frequency negative magnetoresistance and almost 20-fold photosensitivity increase are observed in the second nanostructure. The conductivity anisotropy of the nanostructure GaSe〈htd〉 ( σ|| σ⊥ ) is 10² . Temperature dependence of the real component of complex impedance along the layers at temperature regions –30 < t °C ≤ 10, 10 < t °C ≤ 30, 30 < t °C ≤ 50 demonstrates cardinally different mechanisms of conductivity. Activation energies are 0.35 meV in the low-temperature and 0.69 meV in high-temperature intervals. Non-activated conductivity mechanism is observed within the range of temperatures 10 < t °C ≤ 30. The parameters of the energy spectrum calculated using the Geballe-Pollak theory prior to and after introduction of histidine for two nanostructures are given; it well correlates with the experimental dates.