scholarly journals Excited-State Dynamics of Organic Dyes in Solar Cells

2020 ◽  
Author(s):  
Ahmed M. El-Zohry

Organic dyes are promising candidates for wide applications in solar cells, due to their controlled environmental impact, and low-cost. However, their performances in several solar cell architectures are not high enough to compete with the traditional semiconductor based solar cells. Therefore, several efforts should be gathered to improve the efficiency of these organic dyes. Herein, we discuss several deactivation processes recently found in several organic dyes using optical spectroscopic techniques. These processes are believed to be mostly detrimental for the performance of organic dyes in solar cells. These processes include deactivation phenomena such as isomerization, twisting, and chemical interactions with redox couple. Thus, based on similar studies, more optimized synthetic procedures for organic dyes could be implemented in the near future for high efficient solar cells based on organic dyes.

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Arturo Morales-Acevedo ◽  
Gaspar Casados-Cruz

Solar cells are made of several materials and device structures with the main goal of having maximum efficiency at low cost. Some types of solar cells have shown a rapid efficiency progress whereas others seem to remain constant as a consequence of different factors such as the technological and economic ones. Using information published by the National Renewable Energy Laboratory (NREL) about the increase of solar cells record efficiency, we apply a simple mathematical model to estimate the evolution in the near future for the different cell technologies. Here, as an example, we use data for solar cells made with representative materials and structures of each of the three “PV generations.”


2009 ◽  
Vol 16 (03) ◽  
pp. 381-386 ◽  
Author(s):  
J. B. CHU ◽  
H. B. ZHU ◽  
Z. A. WANG ◽  
Z. Q. BIAN ◽  
Z. SUN ◽  
...  

Single-phase CuInSe 2 films were grown by high vapor selenization of CuIn alloy precursors within a partially closed graphite box. The CuIn precursors were prepared using Cu x In y alloy targets with different composition rates under low vacuum level by a homemade sputtering system. The Cu and In composition rates of the used targets are 11:9, 10:10, and 9:11, respectively. The metallic precursor films were selenized using a two-step temperature profile, i.e. at 250°C and 400–500°C, respectively. The influence of the temperature at the second selenization step on the quality of the CIS absorbing layers was investigated. The CIS films were characterized by X-ray diffractometry, scanning electron microscopy, energy dispersive X-ray analysis, and Raman spectroscopy. The deposited CIS absorbers selenized at a high temperature of 500°C for 30 min exhibited a single-phase chalcopyrite structure with a preferential orientation in the (112) direction. These layers display uniform, large, and densely packed crystals with a grain size of about 3–5 μm. Cadmium sulfide buffer layer was manufactured by chemical bath deposition method. Bilayers ZnO / ZnO : Al were prepared by RF magnetron sputtering deposition. CIS solar cells with an efficiency of about 6.5% were produced without antireflective films. The method to fabricate CIS solar cells by a combination of the low vacuum sputtering deposition and the graphite box selenization process has provided a simple control process and shown a promising potential for developing high efficient and low-cost CuInSe 2 solar cells.


2012 ◽  
Vol 5 (12) ◽  
pp. 9752 ◽  
Author(s):  
Haining Tian ◽  
Erik Gabrielsson ◽  
Peter William Lohse ◽  
Nick Vlachopoulos ◽  
Lars Kloo ◽  
...  

2005 ◽  
Vol 20 (12) ◽  
pp. 3167-3179 ◽  
Author(s):  
Sophie E. Gledhill ◽  
Brian Scott ◽  
Brian A. Gregg

Organic photovoltaic devices are poised to fill the low-cost, low power niche in the solar cell market. Recently measured efficiencies of solid-state organic cells are nudging 5% while Grätzel’s more established dye-sensitized solar cell technology is more than double this. A fundamental understanding of the excitonic nature of organic materials is an essential backbone for device engineering. Bound electron-hole pairs, “excitons,” are formed in organic semiconductors on photo-absorption. In the organic solar cell, the exciton must diffuse to the donor–accepter interface for simultaneous charge generation and separation. This interface is critical as the concentration of charge carriers is high and recombination here is higher than in the bulk. Nanostructured engineering of the interface has been utilized to maximize organic materials properties, namely to compensate the poor exciton diffusion lengths and lower mobilities. Excitonic solar cells have different limitations on their open-circuit photo-voltages due to these high interfacial charge carrier concentrations, and their behavior cannot be interpreted as if they were conventional solar cells. This article briefly reviews some of the differences between excitonic organic solar cells and conventional inorganic solar cells and highlights some of the technical strategies used in this rapidly progressing field, whose ultimate aim is for organic solar cells to be a commercial reality.


2013 ◽  
Vol 1537 ◽  
Author(s):  
Priscilla V. Quintana-Ramírez ◽  
M. C. Arenas

ABSTRACTPoly(3-hexylthiophene)/Titania (P3HT/TiO2) heterojunction has been widely studied in the field of hybrid solar cells. Usually, organic dyes shift the neat TiO2 absorption edge toward the visible range improving the conversion efficiency or/and the TiO2 surface is modified with ligands in order to increase the electron transport. On the other hand, copper sulfide, non-toxic semiconductor, has been included in bulk organic P3HT based solar cell, increasing the photocurrent density of devices. Therefore, we propose the use of copper sulfide in the hybrid TiO2/P3HT heterojunction to determine its effect in the performance of TiO2/P3HT solar cell. Copper sulfide nanocrystals (CuxS) were synthesized at 230 °C, 240 °C and 260 °C and, they were mixed with P3HT in order to form P3HT:CuxS bulk heterojunctions. Scattered grains and irregular morphology in the final topography of the reference device (P3HT/TiO2 heterojunction) were observed by AFM, while a granular morphology and a few pores like craters were observed in the devices containing P3HT:CuxS bulk heterojunctions. Chalcocite phase (Cu2S) was obtained at 230 and 240°C and, digenite (Cu1.8S) phase at 260°C, both copper sulfide phases are very promising for solar cells. Despite this, poor rectifications in the devices were found in the current-voltage curves of the devices containing copper sulfide nanocrystals in contrast to the P3HT/TiO2 cell (device without nanocrystals), it could be due to the current leakage or recombination process in the copper sulfide/TiO2 interface. It suggests future work in order to improve the devices.


2021 ◽  
pp. 1-27
Author(s):  
Marfran C. D. Santos ◽  
João V. M. Mariz ◽  
Raissa V. O. Silva ◽  
Camilo L. M. Morais ◽  
Kássio M. G. Lima

In view of the global pandemic that started in 2020, caused by COVID-19, the importance of the existence of fast, reliable, cheap diagnostic techniques capable of detecting the virus even in the first days of infection became evident. This review discusses studies involving the use of spectroscopic techniques in the detection of viruses in clinical samples. Techniques based on mid-infrared, near-infrared, Raman, and molecular fluorescence are explained and it was demonstrated how they can be used in conjunction with computational tools of multivariate analysis to build models capable of detecting viruses. Studies that used real clinical samples from 2011 to 2021 were analyzed. The results demonstrate the potential of the techniques in detecting viruses. Spectroscopic techniques, as well as chemometric techniques, were also explained. Viral diagnosis based on spectroscopy has interesting advantages compared to standard techniques such as: fast results, no need for reagents, non-destructiveness for the sample, no need for sample preparation, relatively low cost, among others. Several studies have corroborated the real possibility that, in the near future, we may have spectroscopic tools being successfully applied in viral diagnosis.


2014 ◽  
pp. 319-346
Author(s):  
Salahuddin Qazi ◽  
Farhan A. Qazi

Solar radiation is plentiful and a clean source of power. However, despite the first practical use of silicon based solar cell more than 50 years ago, it has not been exploited to its full potential due to the high cost of electrical conversion on a per Watt basis. Many new kinds of photovoltaic cells such as multi-junction solar cells dye –sensitized solar cells and organic solar cell incorporating element of nanotechnology have been proposed to increase the efficiency and reduce the cost. Nanotechnology, in the form of quantum dots, nanorods, nanotubes, and grapheme, has been shown to enhance absorption of sunlight, makes low cost flexible solar panels and increases the efficiency of photovoltaic cells. The chapter reviews the state of current photovoltaic cells and challenges it presents. It also discusses the use of nanotechnology in the application of photovoltaic cells and future research directions to improve the efficiency of solar cells and reduce the cost.


Author(s):  
Salahuddin Qazi ◽  
Farhan A. Qazi

Solar radiation is plentiful and a clean source of power. However, despite the first practical use of silicon based solar cell more than 50 years ago, it has not been exploited to its full potential due to the high cost of electrical conversion on a per Watt basis. Many new kinds of photovoltaic cells such as multi-junction solar cells dye –sensitized solar cells and organic solar cell incorporating element of nanotechnology have been proposed to increase the efficiency and reduce the cost. Nanotechnology, in the form of quantum dots, nanorods, nanotubes, and grapheme, has been shown to enhance absorption of sunlight, makes low cost flexible solar panels and increases the efficiency of photovoltaic cells. The chapter reviews the state of current photovoltaic cells and challenges it presents. It also discusses the use of nanotechnology in the application of photovoltaic cells and future research directions to improve the efficiency of solar cells and reduce the cost.


2020 ◽  
Vol 24 (10) ◽  
pp. 1189-1197
Author(s):  
Naresh Duvva ◽  
Suneel Gangada ◽  
Raghu Chitta ◽  
Lingamallu Giribabu

Limited synthetic steps via low-cost starting materials are needed to develop large-scale light-active materials for efficient solar cells. Here, novel bis(4[Formula: see text]-tert-butylbiphenyl-4-yl)aniline (BBA) based A3B zinc porphyrin (GB) is synthesized and applied as a light harvesting/electron injection material in dye-sensitized solar cells. The GB sensitizer was characterized by various spectroscopic techniques and the optimized device shows [Formula: see text] of 10.98 ± 0.37 mA/cm2 and power conversion efficiency (PCE) of 3.34 ± 0.26%. In addition, performance is enhanced up to ∼3.9% by the addition of co-adsorbent 3a,7a-dihydroxy-5b-cholic acid (chenodeoxycholic acid, CDCA) to minimize [Formula: see text]-[Formula: see text] staking of the planar porphyrin macrocycles. These results demonstrate that novel broad-absorbing light-active material (GB) could be used for indoor solar panels.


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