Numerical Optimization of Gradient Bandgap Structure for CIGS Solar Cell with ZnS Buffer Layer Using Technology Computer-Aided Design Simulation

Joonghyun Park and Myunghun Shin
Additional contact information
Joonghyun Park: School of Electronic Electrical Engineering, College of Information and Communication Engineering, Sungkyunkwan University, Suwon 440-746, Korea
Myunghun Shin: School of Electronics and Information Engineering, Korea Aerospace University, Goyang-city, Gyeonggi-do 412-791, Korea

Energies, 2018, vol. 11, issue 7, 1-10

Abstract: The band structure characteristics of a copper indium gallium sulfur selenide (Cu(In 1 –x Ga x )SeS, CIGS) solar cell incorporating a cadmium-free zinc sulfide (ZnS) buffer layer were investigated using technology computer-aided design simulations. Considering the optical/electrical properties that depend on the Ga content, we numerically demonstrated that the front gradient bandgap enhanced the electron movement over the band-offset of the ZnS interface barrier, and the back gradient bandgap generated a back side field, improving electron transport in the CIGS layer; in addition, the short circuit current density ( J SC ) and open circuit voltage ( V OC ) improved. The simulation demonstrated that the conversion efficiency of a double graded bandgap cell is higher than with uniform or normal/reverse gradient cells, and V OC strongly correlated with the average bandgap in the space charge region (SCR) of CIGS. After selecting V OC from the SCR, we optimized the band structure of the CIGS cell with a Cd-free ZnS buffer by evaluating J SC and the fill factor. We demonstrated that the cell efficiency of the fabricated cell was more than 15%, which agrees well with the simulated results. Our numerical method can be used to design high-conversion efficiency CIGS cells with a gradient band structure and Cd-free buffer layer.

Keywords: CIGS (copper indium gallium selenide); band structure; double graded bandgap; TCAD (technology computer-aided design) simulation; carrier transportation (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2018
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1996-1073/11/7/1785/pdf (application/pdf)
https://www.mdpi.com/1996-1073/11/7/1785/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:11:y:2018:i:7:p:1785-:d:156802

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().