scholarly journals Analysis and modification of defective surface aggregates on PCDTBT:PCBM solar cell blends using combined Kelvin probe, conductive and bimodal atomic force microscopy

2017 ◽  
Vol 8 ◽  
pp. 579-589 ◽  
Author(s):  
Hanaul Noh ◽  
Alfredo J Diaz ◽  
Santiago D Solares
Keyword(s):  
Atomic Force Microscopy ◽  
Solar Cell ◽  
Polymer Solar Cells ◽  
Cell Structure ◽  
Electrical Potential ◽  
Kelvin Probe ◽  
Conductive Atomic Force Microscopy ◽  
Systematic Analysis ◽  
Force Microscopy ◽  
Atomic Force

Organic photovoltaic systems comprising donor polymers and acceptor fullerene derivatives are attractive for inexpensive energy harvesting. Extensive research on polymer solar cells has provided insight into the factors governing device-level efficiency and stability. However, the detailed investigation of nanoscale structures is still challenging. Here we demonstrate the analysis and modification of unidentified surface aggregates. The aggregates are characterized electrically by Kelvin probe force microscopy and conductive atomic force microscopy (C-AFM), whereby the correlation between local electrical potential and current confirms a defective charge transport. Bimodal AFM modification confirms that the aggregates exist on top of the solar cell structure, and is used to remove them and to reveal the underlying active layer. The systematic analysis of the surface aggregates suggests that the structure consists of PCBM molecules.

Analysis of Dislocations in CdZnTe Epitaxial Film with Kelvin Probe and Conductive Atomic Force Microscopy

2020 ◽  
Vol 49 (6) ◽  
pp. 3907-3912
Author(s):  
Kun Cao ◽  
Wanqi Jie ◽  
Gangqiang Zha ◽  
Jiangpeng Dong ◽  
Ruiqi Hu ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Epitaxial Film ◽  
Kelvin Probe ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force

Electrochemical and atomic force microscopy investigations of the effect of CdS on the local electrical properties of CH3NH3PbI3:CdS perovskite solar cells

2017 ◽  
Vol 5 (46) ◽  
pp. 12112-12120 ◽  
Author(s):  
Mingxuan Guo ◽  
Fumin Li ◽  
Lanyu Ling ◽  
Chong Chen
Keyword(s):  
Atomic Force Microscopy ◽  
Solar Cells ◽  
Electrochemical Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Bulk Heterojunction ◽  
Perovskite Solar Cells ◽  
Kelvin Probe ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force

The effect of the incorporated CdS on the local optoelectronic properties of CH3NH3PbI3:CdS bulk heterojunction (BHJ) perovskite solar cells (PSCs) are studied using Kelvin probe force microscopy (KPFM), conductive atomic force microscopy (c-AFM) and electrochemical impedance spectroscopy (EIS).

Distinguishing negatively-charged and highly conductive dislocations in gallium nitride using scanning Kelvin probe and conductive atomic force microscopy

2002 ◽  
Vol 743 ◽  
Author(s):  
Blake S. Simpkins ◽  
Edward T. Yu ◽  
Patrick Waltereit ◽  
James S. Speck
Keyword(s):  
Atomic Force Microscopy ◽  
Kelvin Probe ◽  
Conductive Atomic Force Microscopy ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy ◽  
Spatially Correlated ◽  
Atomic Force ◽  
Scanning Kelvin Probe ◽  
Dislocation Type ◽  
Distinct Features

ABSTRACTScanning Kelvin probe microscopy (SKPM) and conductive atomic force microscopy (C-AFM) are used to image surfaces of GaN grown by molecular beam epitaxy (MBE). Numerical simulations are used to assist in the interpretation of SKPM images. Detailed analysis of the same area using both techniques allows imaging of surface potential variations arising from the presence of negatively charged dislocations and dislocation-related current leakage paths. Correlations between the charge state of dislocations, conductivity of leakage current paths, and possibly dislocation type can thereby be established. Approximately 25% of the leakage paths appear to be spatially correlated with negatively charged dislocation features. This is approximately the level of correlation expected due to spatial overlap of randomly distributed, distinct features of the size observed, suggesting that the negatively charged dislocations are distinct from those responsible for localized leakage paths found in GaN. The effects of charged dislocation networks on the local potential profile is modeled and discussed.

scholarly journals Charge Transport in Intermixed Regions of All-Polymer Solar Cells Studied by Conductive Atomic Force Microscopy

2017 ◽  
Vol 9 (18) ◽  
pp. 15615-15622 ◽  
Author(s):  
Miki Osaka ◽  
Daisuke Mori ◽  
Hiroaki Benten ◽  
Hiroki Ogawa ◽  
Hideo Ohkita ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Solar Cells ◽  
Charge Transport ◽  
Polymer Solar Cells ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force

Electrical investigation of V-defects in GaN using Kelvin probe and conductive atomic force microscopy

2008 ◽  
Vol 93 (2) ◽  
pp. 022107 ◽  
Author(s):  
A. Lochthofen ◽  
W. Mertin ◽  
G. Bacher ◽  
L. Hoeppel ◽  
S. Bader ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Kelvin Probe ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Electrical Investigation ◽  
Atomic Force

Study of the Electrical Properties of Cu2ZnSnS4 (CZTS) Thin Film Using Atomic Force Microscopy (AFM) Techniques

2020 ◽  
Vol 20 (6) ◽  
pp. 3925-3928 ◽  
Author(s):  
Muhunthan Nadarajah ◽  
Om Pal Singh ◽  
Kuldeep Singh Gour ◽  
Vidya Nand Singh
Keyword(s):  
Thin Film ◽  
Atomic Force Microscopy ◽  
Electrical Transport ◽  
Soda Lime ◽  
Czts Thin Film ◽  
Soda Lime Glass ◽  
Kelvin Probe ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force

CZTS is a compound semiconductor made from elements which are plainly available and nonpoisonous having favorable optoelectronic properties for thin film solar cell (TFSC) applications. In this study, Cu-poor CZTS thin film was fabricated on soda lime glass (SLG)/Mo-deposited substrate using cosputtering followed by post sulfurization in H2S atmosphere. Local electrical transport study was carried out by using conductive atomic force microscopy (C-AFM) for small bias voltage (100 mV). Here we observed that most of the dark current (Idark) flow through grain boundaries (GBs) than grain interiors. The positive high current about 3.4 nA and sharp C-AFM signal at the GBs, dips to the zero (0) value at the grain interior. Local surface potential (Vsurface) study was carried out using kelvin probe force microscopy (KPFM), which showed that the positive Vsurface potential about 175 mV in the vicinity of GBs in a Cu-poor CZTS sample. On the basis of these results we inferred a potential landscape (VL) around the GBs. All result shows that due to variation in elemental composition which creates Cu-deficit or CuZn anti site defects at GBs, leads reduced effective band gap (Eeff) than the bulk towards grain inner to GBs.[-2pt]

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