Publication: First Principles Enhanced Electronic Band Structure of Back Contact in CdTe Solar Cells using DFT+U Method
Date
2023
Authors
Ahmad N.I.
Azizan N.
Kar Y.B.
Doroody C.
Arshad S.N.M.
Abdullah A.Z.
Jamal A.
Journal Title
Journal ISSN
Volume Title
Publisher
Institute of Electrical and Electronics Engineers Inc.
Abstract
Cadmium telluride (CdTe) superstrate solar cells have captivated the industry with their remarkable cost-effectiveness. However, optimizing the composition and optoelectrical properties of optimal back surface field (BSF) which can act as a lattice matching interface between the back contact and absorber layer remains a key challenge due to the work function disparity of p-CdTe with metal contacts. In this study, the influence of the Hubbard U parameter on the calculated electronic properties of ZnTe as an optimal BSF compound is presented using the density functional theory (DFT) technique. The Hubbard U value progressively increased from 1 to 4.2 to analyze its influence on the band diagram and Total Density of States (TDOS) in a full comparison of DFT and DFT+U approaches. As the value of Hubbard U increased, the band gap energy exhibited a corresponding increase from 1.20 eV to 2.24 eV, respectively. In comparison, the DFT+U approach with a value of 4.2 exhibited superior accuracy in predicting the band gap of ZnTe, yielding a value of 2.24 eV that closely approximated experimental measurements. This finding reinforces the relevance of employing Hubbard U to achieve more accurate and reliable band gap values for any material doping. � 2023 IEEE.
Description
Keywords
CdTe solar cell , Density Functional Theory , Energy , Energy Band , Hubbard U parameter , Total Density of States , Cadmium telluride , Cost effectiveness , Electronic properties , Energy gap , II-VI semiconductors , Zinc compounds , Back contact , Backsurface field , Cadmium telluride solar cells , Density-functional-theory , Energy , Energy band , Hubbard , Hubbard U parameter , Total density of state , Density functional theory