Temperature dependent behavior of flat and bulk heterojunction organic solar cells

2013 ◽  
Vol 1493 ◽  
pp. 269-273 ◽  
Author(s):  
Johannes Widmer ◽  
Karl Leo ◽  
Moritz Riede

ABSTRACTThe open-circuit voltage of an organic solar cell is increasing with decreasing temperature and with increasing illumination intensity. These dependencies are quantitatively investigated for two types of organic solar cells, one with a flat donor-acceptor heterojunction and one with a mixed layer bulk heterojunction. Zinc-phthalocyanine and C60 are used as donor and acceptor, respectively. A qualitative difference is found for the two geometries. We find that a logarithmic illumination intensity dependence with temperature as a linear pre-factor of the logarithm, which is commonly reported and observed, is applicable for the bulk heterojunction. The flat heterojunction, in contrast, shows a constant illumination intensity pre-factor which is independent of the temperature, and the temperature can be modeled as additional linear summand.

2017 ◽  
Vol 5 (44) ◽  
pp. 23067-23077 ◽  
Author(s):  
Keisuke Ogumi ◽  
Takafumi Nakagawa ◽  
Hiroshi Okada ◽  
Ryohei Sakai ◽  
Huan Wang ◽  
...  

Acceptor–donor–acceptor conjugated magnesium porphyrins showed a power conversion efficiency of 5.73%, high open-circuit voltage of 0.79 V, or an extended incident photon-to-current conversion efficiency spectrum to 1100 nm, depending on the substituents.


2012 ◽  
Vol 1390 ◽  
Author(s):  
Emre Yengel ◽  
M. Saif Islam

ABSTRACTIn bulk heterojunction organic solar cells, open-circuit voltage (Voc) is mainly dependent on the lowest unoccupied molecular orbital and the highest occupied molecular orbital of the donor/acceptor polymer pair in the active layer. However, there are other factors that contribute to considerable reduction in the Voc. The active layer/cathode interface is one of these factors. Previous studies show that e-beam evaporation of the cathode metal contact forms deep interface trap holes in the active layer which increases the Voc of the solar cells. Although these studies show the effect of deeply trapped holes on the Voc, several attempts to elucidate the mechanism behind this effect revealed their subtle and elusive nature. In this work, the effect of cathode contact annealing rate on the overall efficiency is studied. Three different sets of devices were fabricated with varying cathode evaporation rates of 0.1Å/s, 1Å/s and 5Å/s. The results show that at low evaporation rates, atoms in the cathode materials lack adequate energy to form deeply trapped holes. Additionally, above a certain value, the evaporation rate does not have a significant effect on the formation of deeply trapped holes. We also demonstrate that power conversion efficiencies of the devices can be maximized by maintaining the evaporation rate within a specific range.


Author(s):  
Nur Shakina Mohd Shariff ◽  
Puteri Sarah Mohamad Saad ◽  
Mohamad Rusop Mahmood

There has been an increasing interest towards organic solar cells after the discovery of conjugated polymer and bulk-heterojunction concept. Eventhough organic solar cells are less expensive than inorganic solar cells but the power conversion energy is still considered low. The main objective of this research is to investigate the effect of the P3HT’s thickness and concentration towards the efficiency of the P3HT:Graphene solar cells. A simulation software that is specialize for photovoltaic called SCAPS is used in this research to simulate the effect on the solar cells. The solar cell’s structure will be drawn inside the simulation and the parameters for each layers is inserted. The result such as the open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF), efficiency (η), capacitance-voltage (C-V) and capacitance-frequency (C-f) characteristic will be calculated by the software and all the results will be put into one graph.


RSC Advances ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 4106-4112 ◽  
Author(s):  
Tzu-Yen Huang ◽  
Hongping Yan ◽  
Maged Abdelsamie ◽  
Victoria Savikhin ◽  
Sebastian A. Schneider ◽  
...  

The performance of organic solar cells depends on the morphology in bulk heterojunctions, including the polymer degree of crystallinity and the amount of each phase: aggregated donor, aggregated acceptor and molecularly mixed donor : acceptor phase.


2020 ◽  
Vol 181 ◽  
pp. 108523 ◽  
Author(s):  
Dmitry O. Balakirev ◽  
Yuriy N. Luponosov ◽  
Artur L. Mannanov ◽  
Petr S. Savchenko ◽  
Yury Minenkov ◽  
...  

Solar Energy ◽  
2019 ◽  
Vol 184 ◽  
pp. 610-619 ◽  
Author(s):  
J.C. Nolasco ◽  
A. Castro-Carranza ◽  
Y.A. León ◽  
C. Briones-Jurado ◽  
J. Gutowski ◽  
...  

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