THEORETICAL INVESTIGATION INTO QUENCHING OF EXCITED MOLECULES ON THE SURFACE OF A DISK-LIKE NANOPARTICLE

The subject matter of this publication is kinetic modelling of chemica l reactions on the surface of circular plates of a small radius suppos ed to simulate particles of layered semiconductors. To do this, we com bine analytical calculations in the stochastic approximation with comp utations by the Monte Carlo method. The kinetic equations governing qu enching of excited donor molecules by their reaction with accepters ar e derived for the cases of diffusion ''off'' and ''on'', assuming that the efficiency of donor-acceptor interaction depends on the separatio n between the reagents. It is reliably established that donor molecule s decay on a restricted circular surface slower than they do on an unb ounded surface. At large observation times, the kinetics of the diffus ion-controlled reaction can be approximated by an exponential dependen ce with the characteristic rate constant for the process. This kinetic pattern of the diffusion-controlled process at large observation time s differs radically from that of the diffusion-controlled reaction on an infinite surface where the rate constant fails to attain its asympt otic value even at large observation times. By comparing the results o f numerical and analytical calculations, we outlined the range of vali dity of the kinetic equations for chemical processes on a restricted p lane surface.