Oct 28, 2016 - Pros and cons of Dye Sensitized Solar Cells ( DSSC's) ... http://planetsave.com/2012/05/24/solar-power-breakthrough-new-inexpensive- ...
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Perovskite solar cells: a breakthrough in the history of solar cell
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Bukr Ghazi Budwan Abdullah Al Ashraf
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Introduction Structure of Perovskite Material Applications Evolution of Perovskite solar cell (PSC) Pros and cons of Dye Sensitized Solar Cells ( DSSC’s) Development of Perovskite Solar Cell(PSC) Different fabrication techniques of PSC Stability of PSC Conclusion 2
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Perovskite is a calcium titanium oxide mineral composed of calcium titanate, with the chemical formula CaTiO3.
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A perovskite is any material with the same type of crystal structure as calcium titanium oxide (CaTiO3), known as the perovskite structure,
Fig. Perovskite minerals
or (ABX3). »
Perovskites take their name from the mineral, which was first
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discovered in the Ural mountains of Russia by Gustav Rose in 1839 and is named after by Russian mineralogist L. Perovski (1792-1856). 3 http://en.wikipedia.org/wiki/Perovskite_(structure) https://crystalclassics.co.uk/minerals/original_2721.jpg http://en.wikipedia.org/wiki/Lev_Perovski#/media/File:Count_Lev_Alekseevich_Perovski.jpg
Fig. Lev Perovski
» Perovskite-type oxides have the general formula ABX3 (A: alkaline earth metal or lanthanide; B: transition element). A is a large cation, responsible for the thermal resistance, and B is a redox cation, responsible for catalytic activity. B » In the cubic unit cell of this compound, type 'A' atom sits at cube corner positions (0,0,0), type 'B' atom sits at Body Centre position (1/2,1/2,1/2)
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and oxygen atoms sit at Face Centered positions (1/2,1/2,0).
Fig. Crystal structure of organometal perovskite ABX3 with cubic symmetry.
4 Wang et al. (2014), Nanoscale. http://en.wikipedia.org/wiki/Perovskite_(structure)
» Dielectric materials for capacitor, sensor, memory etc. » Piezoelectric materials for pyrodetector, acoustic transducer etc. » Lasers » Photoelectrolysis » Photovoltaics (PVs): PVs application started from 2009
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as Perovskite Solar Cells
Fig. Laser beams
5 http://en.wikipedia.org/wiki/Perovskite_(structure) http://en.wikipedia.org/wiki/Laser#/media/File:LASER.jpg
• Working Principle of Dye sensitized solar cells (DSSCs) o The dye molecules collect light and produce excited electrons which cause a current in the cell. o The iodide electrolyte layer acts as a source for electron replacement.
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• Concern: Instability of electrolytic solution • From the need of stable material in DSSCs Fig. A schematic of dye-sensitized solar cell http://planetsave.com/2012/05/24/solar-power-breakthrough-new-inexpensive-environmentally-friendly-solar-cell
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Advantages: » Low cost. » low light working condition.
Fig. DSSC at laboratory scale
» higher efficiencies at optimum temperatures.
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» Esthetic look.
Disadvantages: » Temperature-sensitive • At low temperatures, the electrolyte can freeze • At high temperatures, the liquid electrolyte expands. » liquid electrolyte causes potential instability, limitation of maximum operation temperature, danger of evaporation. » Additional cost for forming an electrical series connection.
Fig. DSSC Panel 7 http://sysmagazine.com/posts/202836/ http://www.engadget.com/2010/06/10/michael-gratzel-inventor-of-the-dye-sensitized-solar-cell-wins/
» Kojima et al. in 2009 reported the discovery which generated only 3.8% power conversion efficiency (PCE) with a thin layer of perovskite on mesoporous TiO2 as electron-collector .
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η=3.8%
η=6.5%
» In 2011 Lee et al. achieved 6.5% PCE using the same
Fig. Efficiency evolution of different thin-film PV technologies 8
dye-sensitized concept. Kojima et al. (2009), J. Am. Chem.
Lee et al. (2011), Nanoscale
Fan et al. (2014). Photon. Res.
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Fig. Steps of PSC fabrication by dropping method
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Advantages
Drawbacks
Very simple
Limitations in large area coverage
No waste of material
Thickness is hard to control Poor uniformity
Fig. Fabricated film by dropping method 10
η = 3.81 %
η = 3.13 %
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Fig. Nanocrystalline CH3NH3PbBr3 on the Ti02 surface
Fig. Photocurrent- voltage characteristics for cells using CH3NH3PbBr3 /TiO2 (solid line) CH3NH3PbI3 /TiO2 (dashed line)
Perovskite sensitizers on TiO2
Efficiency η (%)
CH3NH3PbBr3
3.13
CH3NH3PbI3
3.81 Kojima et al., (2009), J. Am. Chem. Soc.
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Fig. Doctor-blade by automatic system
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Advantages
Drawbacks
Large area coverage, scalability for roll-toroll production No waste of material
Fig. Doctor-blade by manual settings Micrometric precision of blade
Good uniformity http://forum.tz-uk.com/showthread.php?42525-A-complete-watch/page2
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a
η = 15.1%
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b Fig. J–V characteristics of PSC device under illumination (Red line) and dark condition (Black line) Fig. a) SEM images of MAPbI3 films and b) Cross section of the thin film Deng et al. (2015), Energy Environ. Sci.
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Fig. Injection technique by micropipette
Advantages
Drawbacks
Quick and easy
No controllable thickness
No waste of material
Hard to process large area
http://physics.bgsu.edu/~zamkovm/index.php/research.html
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η = 10.2%
Fig. a: Cross-sectional of a CsSnI3/TiO2 cell and b: Elemental mapping of CsSnI3 into nanoporous TiO2.
Fig. Photocurrent density–voltage (J–V) characteristics of the solar cell devices. 15
Chung et al. (2012), Nature
Fig. Spin coater working stages
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Fig. Spin coater device
Fig. Demonstration of spin coating technique
Advantages
Drawbacks
Good uniformity/reproducibility
Waste of material
Good control on thickness
Hard to process large area
Quick and easy
Film dries fast
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η = 15.7 %
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Fig. SEM of the surface of ITO/ZnO/CH3NH3PbI3 film.
Fig. J–V characteristics of PSC device under illumination (Red line) and dark condition (Black line). 17
Liu et al. (2013), nature photonics
Fig. Vapor deposition device
Fig. Vapor deposition technique
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Advantages
Drawbacks
Good uniformity/reproducibility Good control on thickness Very precise
Expensive device
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η = 15.4% η = 8.6%
Fig. Cross-sectional SEM of a complete photovoltaic device 10/28/2016
Fig. J–V curve for cells
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Liu et al. (2013). Research Letter
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Fan et al. (2014). Photon. Res.
Table: Summary of the device evolution and performance of Perovskite solar cells
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» Preventing from water/moisture could enhance the » Instability - highly sensitive to water (moisture). » Decomposition of Perovskite into CH3NH3I and PbI2.
stability. »
Liu et al. used a Hole Transport Materials(HTM) with long alkyl chains, which can reduce the infiltration of
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water through the HTM layer to the perovskite.
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» Perovskite materials showed superb light-harvesting characteristics » Inexpensive and earth abundant materials » Various fabrication techniques » Fast development with regards to efficiency
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» Could be the leading type of PVs in near future
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