An in situ study of the kinetics of a solid-phase reaction activated by the energy of elastic stresses arisen upon the formation of the Cu/As$_{2}$Se$_{3}$ nanosized film structure

For the first time, the kinetics of a solid-phase chemical reaction activated by the energy of elastic stresses generated upon the formation of the Cu/As$_{2}$Se$_{3}$ nanosized film structure is investigated in situ. It is shown that the time at which a solid-phase chemical reaction starts, as well as the voltage of the Cu/As$_{2}$Se$_{3}$ heterolayer, significantly depends on the thickness of the Cu/As$_{2}$Se$_{3}$ film. At a critical thickness of the Cu/As$_{2}$Se$_{3}$ film, which is equal to 110 nm, a threshold value of the energy of elastic stresses is achieved. Relaxation of this energy over new defects (micropores and microcracks) generated in the film system leads to the activation of a solid-phase chemical reaction and an increase in its rate. A mechanism of the operation of a positive feedback between the chemical reaction in a solid phase and elastic stresses is proposed.