A presentation that includes the background, fabrication, chemistry and future of Perovskite Solar Cells!

1. Presented by,
Dawn John Mullassery, UBC

2. Outline
 Introduction
 History and Evolution
 Fabrication
 Physics, Chemistry and Numbers
 Features
 Drawbacks
 Future

3. The Biggest Solar News!
Science’s top 10 breakthroughs -2013 Nature’s Ten people who
mattered in 2013.
http://www.sciencemag.org/news/2013/12/sciences-top-10-breakthroughs-2013
http://www.nature.com/news/365-days-nature-s-10-1.14367

4. The Numbers!
http://www.ossila.com/pages/perovskites-and-perovskite-solar-cells-an-introduction
http://www.rsc.org/chemistryworld/2015/02/meteoritic-rise-perovskite-solar-cells-under-scrutiny-over-efficiencies

5. Characteristics CdTe CIGS C - Si Perovskites
Raw Material Cost Low Medium Low Low
Finished Material
cost
Low High High Low
Fabrication Cost Medium Medium High Low
Energy Payback
Period
Medium High High Low
Efficiency Medium Medium High High

6. Perovskite
 Any material with a similar structure of CaTiO3
Naturally occurring Perovskite
structure.
 Solar Perovskite – MethylAmmonium Lead Halide

7. History
 Ural Mountains of Russia by Gustav Rose
named after Russian minerologist Lev Perovski
 David Mitzi (1995 – 2002) in IBM-
TFT and LED
 Worked on usage in LEDs and FETs
 Pb toxicity & Sn stability

8. Crystal Structure - CH3NH3PbI3
A perspective of mesoscopic solar cells based on metal chalcogenide quantum dots and organometal-halide perovskites - Jae Hui Rhee,
Chih-Chun Chungand Eric Wei-Guang Diau - NPG Asia Materials (2013) 5, e68; doi:10.1038/am.2013.53

9. Evolution of Perovskites
J. Phys. Chem. Lett. 2013, 4, 3623−3630

10. Evolution of Perovskites
J. Phys. Chem. C, 2014, 118 (11), pp 5615–5625DOI: 10.1021/jp409025w

11. Fabrication
Glass
FTO
TiO2
Perovskite Material
Spiro- OmeTAD
Electron
s
Holes
Nature. 2013, 499, 316

12. Video Courtesy - CEN online

13. Bandgap
DOI: 10.1038/NPHOTON.2014.134, The emergence of perovskite solar cells Martin A. Green1*, Anita Ho-Baillie1 and Henry J.
Snaith2, doi:10.3390/met6010021
G
O
L
D
H
T
M
PerovskiteT
i
O
2
F
T
O

14. DOI: 10.1002/pip.
1.8
eV
1.45 eV
1.6 eV

15. Strong Absorption
DOI: 10.1038/NPHOTON.2014.134

16. DOI: 10.1039/C4TA05246C J. Mater. Chem. A, 2015, 3, 9032-9050

17. Bandgap Tuning - Alloying
MAPb(I1−xBrx)3
DOI: 10.1039/C4EE00942H, Energy Environ. Sci., 2014, 7, 2448-2463, and Chem. Sci.,
2015, 6, 613-617

18. J. Phys. Chem. Lett. 2014, 5, 1628−1635

19. Drawbacks
 Stability
 Lead
 Only “ambient-condition” results

20. Stability- Efficiency is not
everything!
 Normalized absorbance at 410 nm as a function of time for
perovskite films exposed to various relative humidities. Data at 50%
and 20% RH were acquired once per 24 h. The temperature was
measured to be 22.9 ± 0.5 ºC for all measurements.
YANG ET AL, ACSnano VOL. 9 ’ NO. 2 ’ 1955–1963 ’ 2015

21. Stability
The instability of the Methyl Ammonium Lead Halide
remains a major obstacle to commercialization.
In the presence of moisture, the perovskite undergoes rapid
decomposition (15 hours to 2 days) which results in
significant decline in device `performance.
Test Results reveal that unencapsulated perovskite solar
cells reported in 80% drop in PCE over a 24h period.
Even more concerning is the decomposition to PbI2
because it is sparingly soluble in water and this would result
in extreme toxicity.

22. Thermal
degradation of
MAPbI3 and
FAPbI3, when bare
spin-coated films of
each perovskite are
heated in air at
150C for the times
indicated. The
yellow colour that
the MAPbI3
degrades to is lead
Films of MAPbI3 (left)and FAPbI3 (right)
upon exposure to a close to 100%
relative humidity atmosphere for ~15
minutes at room temperature. The
atmosphere was created by pouring
water onto a tissue in a sealed glass
container with the films. Degradation is
evident at an approximately equal rate in
both films.
Giles E. Eperon, Samuel D. Stranks, Henry J. Snaith et.al, Formamidinium lead trihalide: a broadly tunable perovskite for efficient
planar heterojunction solar cells

23.  Perovskite films made with FAI are more thermally stable than MAI. Samples are
left on a hot plate at 120 °C in air with ∼50% relative humidity. The MAI sample
begins to decay at the edges after 6 h, while the FAI showed no sign of decay.
After 17 h, the MAI film nearly completely decayed, while the FAI showed signs of
decay but maintained a darker color. Perovskite films prepared on glass are
approximately 300 nm thick. Photographs are taken with illumination from theDOI: 10.1039/C5TA03577E , J. Mater. Chem. A, 2015, 3, 16097-16103

24. Future is bright!
 High efficiency values
 Good photovoltaic properties
 Stability is an issue – Pb also!
 Tandem Solar Cells – Hitting 40 to 50 %
theoretical efficiency!
 R&D needed

25. Thank You