Interfacial Energy Alignment at the ITO/Ultra-Thin Electron Selective Dielectric Layer Interface and Its Effect on the Efficiency of Bulk-Heterojunction Organic Solar Cells

2016 ◽  
Vol 16 (4) ◽  
pp. 3248-3253 ◽  
Author(s):  
Eiji Itoh ◽  
Yoshinori Goto ◽  
Yusuke Saka ◽  
Katsutoshi Fukuda
Keyword(s):  
Contact Resistance ◽  
Active Layer ◽  
Surface Potential ◽  
Organic Solar Cells ◽  
Indium Tin Oxide ◽  
Bulk Heterojunction ◽  
Electronic Charge ◽  
Photovoltaic Properties ◽  
Potential Measurement ◽  
Layer Interface

We have investigated the photovoltaic properties of an inverted bulk heterojunction (BHJ) cell in a device with an indium-tin-oxide (ITO)/electron selective layer (ESL)/P3HT:PCBM active layer/MoOx/Ag multilayered structure. The insertion of only single layer of poly(diallyl-dimethylammonium chloride) (PDDA) cationic polymer film (or poly(ethyleneimine) (PEI) polymeric interfacial dipole layer) and titanium oxide nanosheet (TN) films as an ESL effectively improved cell performance. Abnormal S-shaped curves were observed in the inverted BHJ cells owing to the contact resistance across the ITO/active layer interface and the ITO/PDDA/TN/active layer interface. The series resistance across the ITO/ESL interface in the inverted BHJ cell was successfully reduced using an interfacial layer with a positively charged surface potential with respect to ITO base electrode. The positive dipole in PEI and the electronic charge phenomena at the electrophoretic deposited TN (ED-TN) films on ITO contributed to the reduction of the contact resistance at the electrode interface. The surface potential measurement revealed that the energy alignment by the transfer of electronic charges from the ED-TN to the base electrodes. The insertion of the ESL with a large positive surface potential reduced the potential barrier for the electron injection at ITO/TN interface and it improved the photovoltaic properties of the inverted cell with an ITO/TN/active layer/MoOx/Ag structure.

Ag Doped Zinc Tin Oxide as Cathode for Organic Photovoltaic Cells

2012 ◽  
Vol 209-211 ◽  
pp. 1719-1722
Author(s):  
Ming Guo Zhang ◽  
Nan Hai Sun
Keyword(s):  
Solar Cells ◽  
Tin Oxide ◽  
Organic Solar Cells ◽  
Indium Tin Oxide ◽  
Bulk Heterojunction ◽  
Indium Tin Oxide Electrode ◽  
Heterojunction Solar Cells ◽  
Visible Part ◽  
Cell Architecture ◽  
Zinc Tin Oxide

A thin Ag layer embedded between layers of zinc tin oxide (ZTO) are compared to cells using an indium tin oxide electrode was investigated for inverted organic bulk heterojunction solar cells employing a multilayer electrode. ZTO/Ag/ ZTO (ZAZ) electrode is the preparation at room temperature, a high transparency in the visible part of the spectrum, and a very low sheet resistance comparable to treated ITO without the need for any thermal post deposition treatment as it is necessary for ITO. The In-free ZAZ electrodes exhibit a favorable work function of 4.3 eV and are shown to allow for excellent electron extraction even without a further interlayer. This renders ZAZ a perfectly suited bottom electrode for inverted organic solar cells with simplified cell architecture.

Deformation and Failure of Bendable Organic Solar Cells

2015 ◽  
Vol 1132 ◽  
pp. 116-124 ◽  
Author(s):  
Joseph Asare ◽  
B. Agyei-Tuffour ◽  
O.K. Oyewole ◽  
G.M. Zebaze-Kana ◽  
W.O. Soboyejo
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Indium Tin Oxide ◽  
Bulk Heterojunction ◽  
Acid Methyl Ester ◽  
Visible Spectrum ◽  
Optical Transmittance ◽  
Hole Injection ◽  
Deformation And Failure ◽  
Organic Layers

This research investigates the effects of bending on the electrical, optical, structural and mechanical properties of flexible organic photovoltaic (OPV) cells. Bulk heterojunction organic solar cells were fabricated on Polyethylene terephthalate (PET) substrates using Poly-3-hexylthiophene: [6, 6]-phenyl-C61-butyric acid methyl ester (P3HT: PCBM) as the active layer and Poly (3, 4-ethylenedioxythiophene) Polystyrenesulfonate (PEDOT: PSS) as the hole injection layer. All the organic layers were deposited by spin coating while the Al cathode was vacuum thermally evaporated. The Indium Tin Oxide (ITO) anode has an average optical transmittance of 85% in the visible spectrum, a sheet resistivity of 60 ohms per square and an average surface roughness of 3nm. The relationship between the optoelectronic performance of the various device layers and the applied mechanical strains has been analyzed. The effects of stress and strain on the current-voltage characteristics of the device and its failure were modeled using the Abaqus software.

scholarly journals D-A-D structured organic molecules with diketopyrrolopyrrole acceptor unit for solution-processed organic solar cells

2014 ◽  
Vol 372 (2013) ◽  
pp. 20130009 ◽  
Author(s):  
Jing Zhang ◽  
Chang He ◽  
Zhi-Guo Zhang ◽  
Dan Deng ◽  
Maojie Zhang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Organic Molecules ◽  
Bulk Heterojunction ◽  
Energy Levels ◽  
Orbital Energy ◽  
Broad Absorption ◽  
Photovoltaic Properties ◽  
Solution Processed ◽  
Highest Occupied Molecular Orbital

Four solution-processable D-A-D structured organic molecules with diketopyrrolopyrrole (DPP) as acceptor unit and triphenylamine (TPA) or (4-hexyl)thieno [3,2-b]thiophene (HTT) as donor unit, DPP8-TPA, DPP8-TPA-OR, DPP6-HTT and DPP8-HTT, were designed and synthesized for the application as donor materials in solution-processed organic solar cells (OSCs). The molecules show broad absorption and relatively lower highest occupied molecular orbital energy levels. Photovoltaic properties of the molecules were investigated by fabricating the bulk-heterojunction OSCs with the molecules as donor and PC 71 BM as acceptor. Power conversion efficiency of the OSC based on DPP8-HTT reached 1.5% under the illumination of AM1.5, 100 mW cm −2 .

scholarly journals Organic materials based on thiophene and benzothiadiazole for organic solar cells. Computational investigations

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
R. Kacimi ◽  
M. Chemek ◽  
A. Azaid ◽  
M.N. Bennani ◽  
K. Alimi ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Bulk Heterojunction ◽  
Chemical Calculation ◽  
Photovoltaic Properties ◽  
Chemical Structures ◽  
Bulk Heterojunction Solar Cell ◽  
Td Dft ◽  
Electronic Parameters ◽  
Homo And Lumo

In this paper, wepresent new organics chemical structures of pendant phenyl ester-substituted thiophene and benzothiadiazole based copolymers leading to donor (D)-acceptor (A) structure-types. Geometrics and photo-physical properties of the studied chemical structure are exploited in the further ground and excited-state. Theoretically, using the DFT and TD-DFT quantum chemical calculation implanted in Gaussian09 software, geometrical and electronic parameters such as the energy of HOMO and LUMO level, the Egap= EHomo- E Lumo and focused electronic parameters of the molecules were determined. It is obvious that the studied molecules show good photovoltaic properties. Thus, studied chemical structures are blended with acceptor compounds such as fullerene and PCBM derivatives in bulk-heterojunction solar cell. Quantic chemical calculations show that the studied compound present good electronic, optical and photovoltaic properties and can be used as potential electron donors in organic solar cells Heterojunction (BHJ).

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