The degree of the transformation of MoO3 films (d= 8–130 nm) increased as the duration (1–140 min) and temperature (373–573 K) of thermal treatment grew and as the film thickness decreased under atmospheric conditions. The thermal treatment of MoO3 films decreased the optical density at λ = 350 nm and caused the appearance of an absorption maximum at λ = 870 nm. A mechanism of thermal transformations of MoO3 was suggested. The mechanism included the formation of the [(Va)++e] center during the preparation and thermal treatment of MoO3 films and thermal electron transition from the valence band to the [(Va)++e] center level with the formation of the [e(Va)++e] center. 相似文献
Preliminary treatment of TlN3(A) with light (λ = 365 nm, I > 1 × 1014 quantum cm−2 s−1) in a vacuum (1 × 10−5 Pa) at 293 K led to the formation of a new long-wave region of spectral sensitivity. The products of photolysis of TlN3(A) thallium and nitrogen formed in the stoichiometric ratio on the sample surface. The topography and kinetics of thallium
accumulation were determined, and the effective rate constants for photolysis evaluated. Measurements of the contact voltage,
current-voltage characteristics, and photocurrent showed that the photolysis of thallium azide resulted in the formation of
TlN3(A)-Tl (photolysis product) microheterogeneous systems. A model of photolysis of TlN3(A) was suggested. According to this model, photolysis included the generation, recombination, and redistribution of nonequilibrium
charge carriers in the contact field and the formation of the end products of photolysis. The limiting stage of photolysis
of TlN3(A) was the diffusion of interstitial thallium cations toward the neutral (Tn Tlm)0 center.
Original Russian Text ? E.P. Surovoi, L.I. Shurygina, L.N. Bugerko, N.V. Borisova, 2009, published in Zhurnal Fizicheskoi
Khimii, 2009, Vol. 83, No. 4, pp. 784–790. 相似文献
Compared to PbN6(Ab), the PbN6(Ab)-Cd system was found to be characterized by a low photolysis rate within the region of intrinsic absorption of PbN6(Ab) and, at the same time, by a broader range of spectral sensitivity of PbN6(Ab), up to 510 nm. Preliminary irradiation by 380-nm light resulted in an increase in the photolysis rate. The photolysis rate constants for the PbN6(Ab)-Cd system were determined. An analysis of the voltammetric characteristics, photocurrent, and contact potential difference made it possible to develop a model of the photolysis of the PbN6(Ab)-Cd system, including the stages of generation, recombination, redistribution of nonequilibrium charge carriers in the contact field, the photoemission of electrons, formation of the photolysis products, and genesis of the PbN6(Ab)-Pb(photolysis product)-Cd system. It was demonstrated that the diffusion of anionic vacancies to neutral Pbn0 sites is the limiting stage of the photolysis of the PbN6(Ab)-Cd system. 相似文献
The thermal treatment of copper films 3–168 nm thick over the temperature range 373–600 K for 1–120 min was shown to result
in the formation of copper(I) oxide. Depending on the initial film thickness and temperature, the kinetic curves of the degree
of transformation were satisfactorily described by a linear, inverse logarithmic, parabolic, or logarithmic law. Contact potential
difference and photo-electromotive force measurements were used to suggest a model including the stages of oxygen adsorption,
charge carrier redistribution in the Cu2O-Cu contact field (negative on the side of Cu2O), and copper(I) oxide formation. 相似文献
Transformations in Pb-WO3 nanodimensional systems are investigated in dependence on the thickness of the Pb and WO3 films, temperature, and thermal treatment duration by means of optical spectroscopy, microscopy, and gravimetry. The contact
potential difference for Pb and WO3 films and the photoelectric power of Pb-WO3 systems is measured. A diagram of the energy bands of Pb-WO3 systems is constructed. A model of thermal transformation for the WO3 films in Pb-WO3 systems is suggested. The model involves the redistribution of equilibrium charge carriers on the contact, formation of the
([(Va)++e]) center during the preparation of a WO3 film, its transformation into a ([e(Va)++e]) center during the formation of the Pb-WO3 systems, and thermal ionization of the ([e(Va)++e]) center. 相似文献
The transformations in nanosized chromium layers at different layer thicknesses (d = 14–154 nm) and thermal treatment temperatures (T = 673–873 K) were studied by optical spectroscopy, microscopy, and gravimetry. The kinetic curves of conversion at different chromium film thicknesses and treatment temperatures are well approximated by the linear, inverse logarithmic, cubic, and logarithmic functions. The contact potential difference for Cr and Cr2O3 films and photo-emf for Cr-Cr2O3 systems were measured. An energy band diagram of Cr-Cr2O3 systems was constructed. A model of thermal transformation was constructed for Cr films that included the stages of oxygen adsorption, charge carrier redistribution in the contact field of Cr-Cr2O3, and chromium(III) oxide formation. 相似文献
Irradiation of silver azide at λ = 365 nm (I > 1 × 1015 quantum cm?2 s?1) in a vacuum (1 × 10?5 Pa) leads to an increase in the rate of photolysis and photoinduced current and the appearance of a new long-wave region of spectral sensitivity. The photolysis products, silver metal and gaseous nitrogen, are formed in a stoichiometric ratio on the surface of silver azide. The rate constants for silver azide photolysis were determined. Measurements of contact potential difference, current—voltage characteristics, photoelectromotive force, and photocurrent showed that AgN3(A1)—Ag (photolysis product) microheterogeneous systems were formed in silver azide photolysis. The limiting stage of silver azide photolysis is the diffusion of interstitial silver cations to the (TnAgm)0 neutral center. 相似文献
Transformations in nanosized manganese films are studied by means of optical spectroscopy, microscopy, and gravimetry at different film thicknesses (d = 4–108 nm) and temperatures of heat treatment (T = 373–673 K). It is found that the kinetic curves of conversion are satisfactorily described in the terms of linear, inverse logarithmic, cubic, and logarithmic laws. The contact potential difference is measured for Mn and MnO films, and photo EMF is measured for Mn–MnO systems. An energy band diagram is constructed for Mn–MnO systems. A model for the thermal transformation of Mn films is proposed that includes stages of oxygen adsorption, the redistribution of charge carriers in the contact field of Mn–MnO, and manganese(II) oxide formation. 相似文献
The transformations in nanosized Ni–MoO3 systems were studied by optical spectroscopy, microscopy, and gravimetry depending on the thickness of the Ni (d = 1–40 nm) and MoO3 (d = 3–50 nm) films, temperature (473–773 K), and thermal treatment time. The contact potential difference was measured for Ni and MoO3 films; photovoltage, for Ni–MoO3 systems. An energy band diagram of the Ni–MoO3 systems was constructed. A model of the thermal transformation of MoO3 films in Ni–MoO3 systems was suggested, which involves a redistribution of equilibrium charge carriers at the contact, formation of a [(Vа)++е] center during the preparation of the MoO3 film, the transformation of this center into an [е(Vа)++е] center during the formation of Ni–MoO3 systems, and the thermal transition of an electron to the level of the [(Vа)++е] center to form an [е(Vа)++е] center.
The gravimetric and optical spectroscopic methods reveals that light irradiation with λ = 300–750 nm and intensity I = 6.9 × 1014–1.1 × 1016 quanta cm−2 s−1 for τ = 1–160 min in atmospheric conditions significantly changes the absorption and reflection spectra and mass of aluminum
films (d = 2–200 nm). The kinetic curves of the degree of conversion versus aluminum film thickness are satisfactorily described in
the inverse logarithmic and parabolic terms. The contact potential difference is measured for Al and Al2O3 films along with the photo-EMF of Al-Al2O3 systems. The suggested model includes the stages of generation and redistribution of nonequilibrium charge carriers in the
contact field of Al-Al2O3 systems, oxygen adsorption, Al3+ diffusion, and Al2O3 formation. 相似文献