Premium
Revealing Surface Modifications of Potassium‐Fluoride‐Treated Cu(In,Ga)Se 2 : A Study of Material Structure, Chemistry, and Photovoltaic Performance
Author(s) -
Aguiar Jeffery A.,
Stokes Adam,
Jiang ChunSheng,
Aoki Toshihiro,
Kotula Paul G.,
Patel Maulik K.,
Gorman Brian,
AlJassim Mowafak
Publication year - 2016
Publication title -
advanced materials interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.671
H-Index - 65
ISSN - 2196-7350
DOI - 10.1002/admi.201600013
Subject(s) - kelvin probe force microscope , materials science , crystallite , thin film , depletion region , atom probe , conductive atomic force microscopy , copper , semiconductor , analytical chemistry (journal) , alkali metal , deposition (geology) , scanning electron microscope , nanotechnology , optoelectronics , atomic force microscopy , chemistry , metallurgy , composite material , environmental chemistry , transmission electron microscopy , paleontology , organic chemistry , sediment , biology
The effects of alkali post‐deposition treatments and device properties for polycrystalline thin film Cu(In,Ga)Se 2 have been investigated. It is reported that these surface treatments lead to differences in interface chemistry and device properties. The behavior of defects in the space charge region as a function of different growth parameters is investigated by correlative analytical microscopy. The latter combines electron microscopy based imaging, Kelvin probe force microscopy, and atom probe tomography. Alkali treatments lead to copper depletion and consequent sharpening of the compositional profiles, and the measured electric potential differences of exposed Cu(In 1–x ,Ga x )Se 2 surfaces. Measurable differences in resistivity and potential have also been observed, which are expected to relate to the improved open‐circuit voltage, fill‐factor, and device efficiency. This study frames one perspective as to why post‐deposition alkaline treatments lead to copper depletion, a mildly n‐type semiconductor interface, and higher efficiency for a Cu(In,Ga)Se 2 thin‐film photovoltaic device.