Nanovolume positron traps in glassy-like As2Se3

A meaningful interpretation of positron lifetime characteristics for glassy-like g-As2Se3 is developed taking into account theoretical calculations of Jensen et al. [J. Non-Cryst. Solids 170 (1994) 57] for positrons trapped by so-called free-volume vacancy-type defects (vacancies and vacancy-type clusters) in orthorhombic As2Se3 and void volume distribution for 146-atoms layer-biased and random computer models of amorphous As2Se3 performed by Popescu yet in 1980. It is concluded that the obtained experimental data can be divided into two groups with close lifetime characteristics but different positron trapping coefficients. This feature can be well explained in terms of average positron lifetime by applying two-state positron trapping model for mathematical treatment of the experimental data.