First-principles DFT + GW study of the Te antisite in CdTe

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• 作者：Mauricio A. Flores^a ; ^b ; ^{mauricio.flores@ug.uchile.cl" class="auth_mail" title="E-mail the corresponding author} ; Walter Orellana^c ; Eduardo Mené ; ndez-Proupin^d
• 关键词：CdTe ; Te antisite ; Gap state ; Carrier recombination ; DFT  ; +  ; GW
• 刊名：Computational Materials Science
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：125
• 期：Complete
• 页码：176-182
• 全文大小：2455 K

文摘

Formation energies, charge transitions levels, and quasiparticle defect states of the tellurium antisite (Te_Cd)$({\text{Te}}_{\text{Cd}})$ in CdTe are addressed within the DFT + GW   formalism. We find that (Te_Cd)$({\text{Te}}_{\text{Cd}})$ induces a (+2/0) deep level at 0.99 eV above the valence band maximum, exhibiting a negative-U effect. Moreover, the calculated zero-phonon line for the excited state of (Te_Cd)⁰${({\text{Te}}_{\text{Cd}})}^0$ corresponds closely with the ∼1.1 eV band, visible in both luminescence and absorption experiments. Our results differ from previous theoretical studies, mainly due to the well-known band gap error and the incorrect position of the band edges predicted by standard DFT calculations.