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.
Original language | American English |
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Pages (from-to) | 1744-1747 |
Number of pages | 4 |
Journal | Solid State Communications |
Volume | 152 |
Issue number | 18 |
DOIs | |
State | Published - Sep 2012 |
NREL Publication Number
- NREL/JA-5200-55145
Keywords
- A. CdTe
- C. Grain boundary
- D. Gap state
- E. DFT calculation