Theoretical studies on intrinsic electron traps in amorphous tantalum pentoxide

L Li and XC Chen and G Zeng and GX Yang and XQ Liu, PHYSICS LETTERS A, 525, 129945 (2024).

DOI: 10.1016/j.physleta.2024.129945

Charge traps in amorphous tantalum pentoxide (Ta2O5) can degrade electrical performance of electronic devices. An earlier study shows that a local region consisting of several interconnected TaOn polyhedrons can act as an electron trapping site in Ta2O5 cell, indicating polymer-like intrinsic electron traps (IETs). With first- principle calculations, in conjunction with molecular dynamic calculations, this work investigates the one-electron trapping behaviours of Ta2O5 in detail, including atomic configurations and electronic properties. Stable states of Ta2O5 cells with an extra electron demonstrate the existence of point-like IETs, such as a single TaO6 polyhedron. An electron trapping at an IET can produce an electron state typically hundreds of meV below the conductive band minimum. The concentration of IETs is found to decrease exponentially with decreasing energy, and the total concentration is suggested to be of the order of 10(20) cm(-3).

Return to Publications page