Title
Material Property Changes in Defects Caused by Reverse Bias Exposure of CIGS Solar Cells
Author
Bakker, K.
Nilsson Ahman, H.
Aantjes, K.
Barreau, N.
Weeber, A.W.
Theelen, M.
Publication year
2019
Abstract
Partial shading of Cu(In,Ga)Se2 modules can lead to the formation of reverse bias induced wormlike defects. These wormlike defects act as local shunts and permanently decrease module output. A good understanding of the formation and propagationmechanisms of these defects is needed in order tomitigate the negative effects, or to prevent these defects from forming. In this article, wormlike defects were formed on small nonencapsulated cells by exposing them to reverse bias conditions. Scanning electron microscopy-energy-dispersive X-ray spectroscopy measurements showed a rearrangement of elements: Indium, gallium, and copper were replaced by cadmium, whereas selenium was replaced by sulfur in the area around the defect. Moreover, additional electronic-defect levels were found in that area with spectrally resolved photoluminescence spectroscopy. Based on the material changes in the area close to the wormlike defects, a propagation mechanism is proposed. The model assumes a chemical reaction as the driving force for propagation instead of melting because of ohmic heating
Subject
Energy Efficiency
Energy / Geological Survey Netherlands
Cadmium
Electric breakdown
Photoluminescence (PL)
Photovoltaic (PV) cells
Reliability
Thin film devices.
To reference this document use:
http://resolver.tudelft.nl/uuid:cc81f3f2-a92b-4fc9-9197-2e12b0fd9bbc
TNO identifier
875665
Source
IEEE Journal of Photovoltaics, 9 (6), 1-5
Document type
article