NETWORKS OF NANOPARTICLES IN ORGANIC – INORGANIC COMPOSITES: ALGORITHMIC EXTRACTION AND STATISTICAL ANALYSIS

The rising global demand in energy and the limited resources in fossil fuels require new technologies in renewable energies like solar cells. Silicon solar cells offer a good efficiency but suffer from high production costs. A promising alternative are polymer solar cells, due to potentially low production costs and high flexibility of the panels. In this paper, the nanostructure of organic–inorganic composites is investigated, which can be used as photoactive layers in hybrid–polymer solar cells. These materials consist of a polymeric (OC1C10-PPV) phase with CdSe nanoparticles embedded therein. On the basis of 3D image data with high spatial resolution, gained by electron tomography, an algorithm is developed to automatically extract the CdSe nanoparticles from grayscale images, where we assume them as spheres. The algorithm is based on a modified version of the Hough transform, where a watershed algorithm is used to separate the image data into basins such that each basin contains exactly one nanoparticle. After their extraction, neighboring nanoparticles are connected to form a 3D network that is related to the transport of electrons in polymer solar cells. A detailed statistical analysis of the CdSe network morphology is accomplished, which allows deeper insight into the hopping percolation pathways of electrons.

Download Full-text

Hole Transport Behaviour of Various Polymers and Their Application to Perovskite-Sensitized Solid-State Solar Cells

Journal of Nanomaterials ◽

10.1155/2018/7545914 ◽

2018 ◽

Vol 2018 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Jeongmin Lim ◽

Seong Young Kong ◽

Yong Ju Yun

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Solid State ◽

Perovskite Solar Cell ◽

Hole Transport ◽

Transport Layer ◽

Hole Transport Layer ◽

Good Efficiency ◽

Promising Alternative ◽

Transport Behaviour

Inorganic-organic mesoscopic solar cells become a promising alternative for conventional solar cells. We describe a CH3NH3PbI3 perovskite-sensitized solid-state solar cells with the use of different polymer hole transport materials such as 2,2′,7,7′-tetrakis-(N,N-di-p-methoxyphenyl-amine)-9,9′-spirobifluorene (spiro-OMeTAD), poly(3-hexylthiophene-2,5-diyl) (P3HT), and poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7). The device with a spiro-OMeTAD-based hole transport layer showed the highest efficiency of 6.9%. Interestingly, the PTB7 polymer, which is considered an electron donor material, showed dominant hole transport behaviors in the perovskite solar cell. A 200 nm thin layer of PTB7 showed comparatively good efficiency (5.5%) value to the conventional spiro-OMeTAD-based device.

Download Full-text

Modeling the morphology evolution of organic solar cells

GAMM Archive for Students ◽

10.14464/gammas.v1i1.419 ◽

2019 ◽

Vol 1 (1) ◽

pp. 18-27

Author(s):

Kai Bergermann

Keyword(s):

Solar Cells ◽

Organic Solar Cells ◽

Chemical Potential ◽

Phase Field Model ◽

Linear Partial Differential Equation ◽

Production Costs ◽

Morphology Evolution ◽

Major Drawback ◽

Promising Alternative ◽

Potential Term

Organic solar cells present a promising alternative for the generation of solar energy at lower material and production costs compared to widely used silicon-based solar cells. The major drawback of organic solar cells currently is a lower rate of energy conversion. Thus many research projects aim to improve the achievable efficiency. In this work a phase field model is used to mathematically describe the morphology evolution of the active layer composed of polymer as electron-donor and fullerene as electron-acceptor. The derivation of a chemical potential term and a surface energy term for the polymer-fullerene solution using the Flory-Huggins theory forms the basis to employ the Cahn-Hilliard equation. After including several specifics of the application in this non-linear partial differential equation of fourth order, an implementation of the model using the FEM solver software FEniCS provides some simulation results that qualitatively match results from the literature.

Download Full-text