Origin of the electrical activity of iron atoms in vitreous arsenic selenide

Electronic exchange between centres of iron in the vitreous arsenic selenide

“…Figure 7 presents the dependence of the shift of the Fermi level from the middle of the band gap δE = (E opt )/2 -E σ on the iron concentration. As can be seen from the figure, when the iron concentration increases, the Fermi level smoothly approaches its limiting position, which is distant from the middle of the band gap by a value of 0.57 ± 0.03 eV (Marchenko, Rabchanova, Seregin et al 2016). .…”

“…For undoped glass E opt ≈ 2E σ and the current transfer, according to the sign of Seebeck coefficient, is realised by holes. The introduction of iron into glass leads to a change in the sign of the current carriers (the current transfer, according to the sign of the Seebeck coefficient, is realised by electrons) and to a decrease in the electro conductance activation energy (Marchenko, Rabchanova, Seregin et al 2016). Figure 7 presents the dependence of the shift of the Fermi level from the middle of the band gap δE = (E opt )/2 -E σ on the iron concentration.…”

“…2). If N Fe ≤ 2 at.%, then all the donor iron centres are ionised and only the iron Fe 2+ state is observed in the 57 Fe Mössbauer spectra ( Fig.4) (Marchenko, Rabchanova, Seregin et al 2016). The fraction of the Fe 2+ ions can be calculated using the following equation:…”

“…In particular, the electrical activity of iron impurity atoms was discovered in glassy films of arsenic selenide back in 1990 (Turaev, Seregin, Nasredinov 1990). Later, we undertook studies of both the nature of the electrical activity of iron (Marchenko, Luzhkov, Rasnyuk et al 2017;Marchenko, Terukov, Egorova et al 2017) and the mechanism of electrical activity of the different states of iron in As 2 Se 3 (Bobokhuzhaev, Rabchanova, Seregin, Shaldenkova 2015;Marchenko, Rabchanova, Seregin et al 2016). In this paper, we consider all the results we obtained (Bobokhuzhaev, Rabchanova, Seregin, Shaldenkova 2015;Marchenko, Rabchanova, Seregin et al 2016;Marchenko, Luzhkov, Rasnyuk et al 2017, Marchenko, Terukov, Egorova et al 2017Marchenko, Nasredinov, Seregin 2018;Turaev, Seregin, Nasredinov 1990) from a single perspective.…”