Open AccessInterface Analysis of Cu(In,Ga)Se 2 and ZnS Formed Using Sulfur Thermal Cracker
Author(s) -
Cho DaeHyung,
Lee WooJung,
Wi JaeHyung,
Han Won Seok,
Kim Tae Gun,
Kim Jeong Won,
Chung YongDuck
Publication year - 2016
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.16.2515.0031
Subject(s) - copper indium gallium selenide solar cells , buffer (optical fiber) , materials science , sputtering , layer (electronics) , optoelectronics , conduction band , solar cell , fabrication , band gap , thin film , analytical chemistry (journal) , electron , chemistry , nanotechnology , electrical engineering , physics , engineering , medicine , alternative medicine , pathology , quantum mechanics , chromatography
We analyzed the interface characteristics of Zn‐based thin‐film buffer layers formed by a sulfur thermal cracker on a Cu(In,Ga)Se 2 (CIGS) light‐absorber layer. The analyzed Zn‐based thin‐film buffer layers are processed by a proposed method comprising two processes — Zn‐sputtering and cracker‐sulfurization. The processed buffer layers are then suitable to be used in the fabrication of highly efficient CIGS solar cells. Among the various Zn‐based film thicknesses, an 8 nm–thick Zn‐based film shows the highest power conversion efficiency for a solar cell. The band alignment of the buffer/CIGS was investigated by measuring the band‐gap energies and valence band levels across the depth direction. The conduction band difference between the near surface and interface in the buffer layer enables an efficient electron transport across the junction. We found the origin of the energy band structure by observing the chemical states. The fabricated buffer/CIGS layers have a structurally and chemically distinct interface with little elemental inter‐diffusion.