Domain-like ultra-thin layers deposited electrochemically from carbazole-functionalized perylene bisimides for electron collection in inverted photovoltaic cells

2013 ◽  
Vol 49 (56) ◽  
pp. 6283 ◽  
Author(s):  
Tao Feng ◽  
Biao Xiao ◽  
Ying Lv ◽  
Zengqi Xie ◽  
Hongbin Wu ◽  
...  
1991 ◽  
Vol 69 (3-4) ◽  
pp. 538-542 ◽  
Author(s):  
C. H. Champness ◽  
Z. A. Shukri ◽  
C. H. Chan

In Se–CdO photovoltaic cells, the electron diffusion length Ln in the selenium absorber layer has been determined from measurements of capacitance C and photocurrent under monochromatic illumination by variation of applied reverse bias. If penetrating incident light of band-gap wavelength is used, a plot against 1/C of the illuminated-to-dark current change ΔI yields a straight line over a certain range of bias values. Extrapolation of this line to the 1/C axis yields Ln. It was found in the fabrication of the Se–CdO cells that increasing the substrate temperature from 100 to 140 °C during the selenium deposition resulted in an increase in the cell photovoltaic output. Capacitance and ΔI measurements on these cells showed an increase in diffusion length with substrate temperature, indicating that the increased cell performance was due to improved electron collection in the selenium layer.


2019 ◽  
Vol 293 ◽  
pp. 51-64
Author(s):  
Pawel Jarka ◽  
Tomasz Tański ◽  
Bartlomiej Hrapkowicz ◽  
Barbara Hajduk ◽  
Kamil Bystroń ◽  
...  

The aim of this work is to present the influences of composition of the material and manufacturing technology conditions of the organic photovoltaics devices (OPv) with the organic and hybrid bulk heterojunction on the active layers properties and cells performance. The layers were produced by using small molecular compounds: the metal-phthalocyanine (MePc) and perylene derivatives (PTCDA) and the titanium dioxide (TiO2) nanoparticles. Two kinds of metal phthalocyanines (NiPc, TiOPc) were used as donor material and pperylenetetracarboxylic dianhydride (PTCDA) as an acceptor. The used manufacturing technique allowed to employ thin layers of materials in a fast deposition process. Bulk heterojunction was created by simultaneously applying the MePc:PTCDA materials during the evaporation of the components mixture.The research was based on the estimate of composition of bulk heterojunction, the examination of the surface morphology of the used layers and optical properties studies of the heterojunction and its implementation to photovoltaic architecture. The produced photovoltaic cells parameters were determined on the basis of current - voltage characteristics.The researches of structure of obtained layers were conducted by using scanning electron microscope (SEM) and transmission electron microscopy (TEM). The quantitative determination of surface topography by determining RMS and Ra coefficients were performed by atomic force microscopy (AFM). In order to determine the optical properties of the films the UV-Visible spectroscope have been utilized. Current - voltage characteristics were employed to determine the basic photovoltaic parameters using a dedicated device.The paper describes the influence of the individual components sharing the bulk heterojunction on its structure, optical properties and morphology of surface. In addition it allows for linking active layers properties with the parameters of the photovoltaic cells. The obtained results suggest the possibility of developing the utilized materials and technology in the further works on photovoltaic structures.


1994 ◽  
Vol 47 (10) ◽  
pp. 1869 ◽  
Author(s):  
D Matthews ◽  
A Kay ◽  
M Gratzel

A new technique for forming porous thin layers of nano -colloidal titanium dioxide on electronically conducting glass was developed. This technique uses constant-current electrophoretic deposition from a dispersion of Degussa P-25 titanium dioxide in 2-methoxyethanol followed by air-drying and annealing. Dye-sensitized TiO2 photovoltaic cells constructed with these films gave current-voltage characteristics comparable with those of films produced by other techniques. A 30 cm2 prototype photovoltaic cell was constructed with electrophoretically deposited TiO2, and tested. Measurement of the dark current and photocurrent enabled the calculation of the light current, and the effect of both the dark current and the series resistance on the cell performance was demonstrated.


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1360 ◽  
Author(s):  
Sukrit Sucharitakul ◽  
Rangsan Panyathip ◽  
Supab Choopun

Zinc oxide (ZnO) offers a great potential in several applications from sensors to Photovoltaic cells thanks to the material’s dependency, to its optical and electrical properties and crystalline structure architypes. Typically, ZnO powder tends to be grown in the form of a wurtzite structure allowing versatility in the phase of material growths; albeit, whereas in this work we introduce an alternative in scalable yet relatively simple 2D hexagonal planed ZnO nanoflakes via the electrochemical deposition of commercially purchased Zn(NO3)2 and KCl salts in an electrochemical process. The resulting grown materials were analyzed and characterized via a series of techniques prior to thermal annealing to increase the grain size and improve the crystal quality. Through observation via scanning electron microscope (SEM) images, we have analyzed the statistics of the grown flakes’ hexagonal plane’s size showing a non-monotonal strong dependency of the average flake’s hexagonal flakes’ on the annealing temperature, whereas at 300 °C annealing temperature, average flake size was found to be in the order of 300 μm2. The flakes were further analyzed via transmission electron microscopy (TEM) to confirm its hexagonal planes and spectroscopy techniques, such as Raman Spectroscopy and photo luminescence were applied to analyze and confirm the ZnO crystal signatures. The grown materials also underwent further characterization to gain insights on the material, electrical, and optical properties and, hence, verify the quality of the material for Photovoltaic cells’ electron collection layer application. The role of KCl in aiding the growth of the less preferable (0001) ZnO is also investigated via various prospects discussed in our work. Our method offers a relatively simple and mass-producible method for synthesizing a high quality 2D form of ZnO that is, otherwise, technically difficult to grow or control.


Author(s):  
K. T. Tokuyasu

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).


Author(s):  
S.J. Splinter ◽  
J. Bruley ◽  
P.E. Batson ◽  
D.A. Smith ◽  
R. Rosenberg

It has long been known that the addition of Cu to Al interconnects improves the resistance to electromigration failure. It is generally accepted that this improvement is the result of Cu segregation to Al grain boundaries. The exact mechanism by which segregated Cu increases service lifetime is not understood, although it has been suggested that the formation of thin layers of θ-CuA12 (or some metastable substoichiometric precursor, θ’ or θ”) at the boundaries may be necessary. This paper reports measurements of the local electronic structure of Cu atoms segregated to Al grain boundaries using spatially resolved EELS in a UHV STEM. It is shown that segregated Cu exists in a chemical environment similar to that of Cu atoms in bulk θ-phase precipitates.Films of 100 nm thickness and nominal composition Al-2.5wt%Cu were deposited by sputtering from alloy targets onto NaCl substrates. The samples were solution heat treated at 748K for 30 min and aged at 523K for 4 h to promote equilibrium grain boundary segregation. EELS measurements were made using a Gatan 666 PEELS spectrometer interfaced to a VG HB501 STEM operating at 100 keV. The probe size was estimated to be 1 nm FWHM. Grain boundaries with the narrowest projected width were chosen for analysis. EDX measurements of Cu segregation were made using a VG HB603 STEM.


1993 ◽  
Vol 3 (11) ◽  
pp. 1633-1645 ◽  
Author(s):  
Yu. A. Buyevich ◽  
A. Yu. Zubarev

1983 ◽  
Vol 44 (C9) ◽  
pp. C9-487-C9-492
Author(s):  
G. Haneczok ◽  
R. Kuśka ◽  
R. Kwiatkowski ◽  
J. W. Moro

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