Title of article :
Possible effects of oxygen in Te-rich Σ3 (112) grain boundaries in CdTe
Author/Authors :
Feng، نويسنده , , Chunbao and Yin، نويسنده , , Wan-Jian and Nie، نويسنده , , Jinlan and Zu، نويسنده , , Xiaotao and Huda، نويسنده , , Muhammad N. and Wei، نويسنده , , Su-Huai and Al-Jassim، نويسنده , , Mowafak M. and Yan، نويسنده , , Yanfa، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2012
Abstract :
Using density functional theory calculation, we show that oxygen (O) exhibits an interesting effect in CdTe. The Te atoms with dangling bonds in a Te-rich rich Σ3 (112) grain boundary (GB) create deep gap states due to strong interaction between Te atoms. However, when such a Te atom is substituted by an O atom, the deep gap states can be shifted toward the valence band, making the site no longer a harmful non-radiative recombination center. We find that O atoms prefer energetically substituting these Te atoms and induce significant lattice relaxation due to their smaller atomic size and stronger electronegativity, which effectively reduces the anion–anion interaction. Consequently, the deep gap states are shifted to lower energy regions close to or even below the top of the valence band.
Keywords :
D. Gap state , A. CdTe , C. Grain boundary , E. DFT calculation
Journal title :
Solid State Communications
Journal title :
Solid State Communications