Small Molecule with Extended Alkyl Side Substituents for Organic Solar Cells

MRS Advances ◽  
2016 ◽  
Vol 2 (42) ◽  
pp. 2253-2259 ◽  
Author(s):  
Chenyu Zheng ◽  
Ishita Jalan ◽  
Jeremy A. Cody ◽  
Christopher J. Collison
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Small Molecules ◽  
Organic Solar Cells ◽  
Hole Mobility ◽  
Superior Performance ◽  
Side Chain ◽  
Alkyl Side Chain ◽  
Transmission Electron ◽  
Absorbance Spectra

ABSTRACTIn this work, we have investigated two aniline based squaraine molecules, DBSQ(OH)2 and DHSQ(OH)2, for their potential application in organic photovoltaics. These two squaraine molecules are only different in side chain length (i.e. butyl vs. hexyl). Yet, their solar cell properties are drastically different (PCE = 3.6% vs. 1.9%). We have further investigated the reason behind the superior performance of DBSQ(OH)2 in absorbance spectra, hole mobility characterization and transmission electron microscopy. The results show that DBSQ(OH)2 has a higher hole mobility (5.1×10-4 cm2/V•s vs. 1.4×10-4 cm2/V•s) and is able to mix well with the fullerene acceptor compared to DHSQ(OH)2. Our work shows clearly that the long solubilizing alkyl side chain might be detrimental for OPV performance and that shorter side chains with enough solubility have great value when designing small molecules.

Nanomorphology of P3HT:PCBM-based Organic Solar Cells Analyzed by Low-Energy Scanning Transmission Electron Microscopy

2012 ◽  
Vol 18 (S2) ◽  
pp. 1234-1235 ◽  
Author(s):  
M. Pfaff ◽  
E. Müller ◽  
P. Müller ◽  
D. Gerthsen ◽  
M.G. Klein ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solar Cells ◽  
Organic Solar Cells ◽  
Scanning Transmission Electron Microscopy ◽  
Low Energy ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Role of Si1−xGex Buffer Layer in Determining Electrical Characteristics of Modulation-Doped p-Si0. 5Ge0.5/Ge/Si1−xGex Heterostructures

1990 ◽  
Vol 198 ◽  
Author(s):  
Eiichi Murakami ◽  
Hiroyuki Etoh ◽  
Akio Nishida ◽  
Kiyokazu Nakagawa ◽  
Masanobu Miyao
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Raman Spectroscopy ◽  
Buffer Layer ◽  
Hole Mobility ◽  
Threading Dislocations ◽  
Electrical Characteristics ◽  
Transmission Electron

ABSTRACTElectrical characteristics of modulation-doped p-Si0.5Ge0.5/Ge/Si1−x Gex heterostructures are examined in relation to Si fraction (1−X) and thickness (dB)of the buffer layer (Si1−xGex), using Raman spectroscopy and transmission electron microscopy. Strain-induced enhancement of hole mobility and concentration is observed in 1-X≦0.25. However, their decrease in 1-X≦0.25 and for small dB values is also observed, which is attributed to the increase in threading dislocations. As a result, a maximum hole mobility of 7600 cm2/Vs at 77 K is obtained at 1-X=0.25 and dB=1μm.

scholarly journals Unraveling the Complex Nanomorphology of Ternary Organic Solar Cells with Multimodal Analytical Transmission Electron Microscopy

Solar RRL ◽  
2020 ◽  
Vol 4 (6) ◽  
pp. 2000114
Author(s):  
Stefanie Rechberger ◽  
Nicola Gasparini ◽  
Ranbir Singh ◽  
Min Kim ◽  
Christos L. Chochos ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solar Cells ◽  
Organic Solar Cells ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron

scholarly journals Atomic-level engineering and imaging of polypeptoid crystal lattices

2019 ◽  
Vol 116 (45) ◽  
pp. 22491-22499 ◽  
Author(s):  
Sunting Xuan ◽  
Xi Jiang ◽  
Ryan K. Spencer ◽  
Nan K. Li ◽  
David Prendergast ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Rational Design ◽  
Bromine Atom ◽  
Atomic Level ◽  
Dynamics Simulation ◽  
Side Chain ◽  
Substitution Pattern ◽  
Cryogenic Transmission Electron Microscopy ◽  
Transmission Electron

Rational design of supramolecular nanomaterials fundamentally depends upon an atomic-level understanding of their structure and how it responds to chemical modifications. Here we studied a series of crystalline diblock copolypeptoids by a combination of sequence-controlled synthesis, cryogenic transmission electron microscopy, and molecular dynamics simulation. This family of amphiphilic polypeptoids formed free-floating 2-dimensional monolayer nanosheets, in which individual polymer chains and their relative orientations could be directly observed. Furthermore, bromine atom side-chain substituents in nanosheets were directly visualized by cryogenic transmission electron microscopy, revealing atomic details in position space inaccessible by conventional scattering techniques. While the polypeptoid backbone conformation was conserved across the set of molecules, the nanosheets exhibited different lattice packing geometries dependent on the aromatic side chain para substitutions. Peptoids are inherently achiral, yet we showed that sequences containing an asymmetric aromatic substitution pattern pack with alternating rows adopting opposite backbone chiralities. These atomic-level insights into peptoid nanosheet crystal structure provide guidance for the future design of bioinspired nanomaterials with more precisely controlled structures and properties.

Nanomorphology of P3HT:PCBM-Based Absorber Layers of Organic Solar Cells after Different Processing Conditions Analyzed by Low-Energy Scanning Transmission Electron Microscopy

2012 ◽  
Vol 18 (6) ◽  
pp. 1380-1388 ◽  
Author(s):  
Marina Pfaff ◽  
Michael F.G. Klein ◽  
Erich Müller ◽  
Philipp Müller ◽  
Alexander Colsmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Transmission Electron Microscopy ◽  
Solar Cells ◽  
Organic Solar Cells ◽  
Scanning Transmission Electron Microscopy ◽  
Low Energy ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

AbstractIn this study the nanomorphology of P3HT:PC61BM absorber layers of organic solar cells was studied as a function of the processing parameters and for P3HT with different molecular weight. For this purpose we apply scanning transmission electron microscopy (STEM) at low electron energies in a scanning electron microscope. This method exhibits sensitive material contrast in the high-angle annular dark-field (HAADF) mode, which is well suited to distinguish materials with similar densities and mean atomic numbers. The images taken with low-energy HAADF STEM are compared with conventional transmission electron microscopy and atomic force microscopy images to illustrate the capabilities of the different techniques. For the interpretation of the low-energy HAADF STEM images, a semiempirical equation is used to calculate the image intensities. The experiments show that the nanomorphology of the P3HT:PC61BM blends depends strongly on the molecular weight of the P3HT. Low-molecular-weight P3HT forms rod-like domains during annealing. In contrast, only small globular features are visible in samples containing high-molecular-weight P3HT, which do not change significantly after annealing at 150°C up to 30 min.

Features of the Fine Structure of the Active Layers of Organic Solar Cells

2016 ◽  
Vol 712 ◽  
pp. 176-181
Author(s):  
Alexander I. Smirnov ◽  
Natalya V. Plotnikova ◽  
Vladimir G. Burov ◽  
Nikita V. Martyushev
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solar Cells ◽  
Fine Structure ◽  
Thermal Treatment ◽  
Organic Solar Cells ◽  
Crystalline Phase ◽  
Active Layers ◽  
Transmission Electron ◽  
Diffusion Redistribution

The article is devoted to investigation of fine structure of the active layers of organic solar cells. By using atomic forth microscopy (AFM) and transmission electron microscopy (TEM) it is clearly shown that thermal treatment of active layers at 150 °C for 10 minutes leads to increasing their crystallinity. During annealing processes of diffusion redistribution of the film components are activated, and this is accompanied by both the growth of the original crystalline phase and the formation of new crystals.

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

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