Perovskite Solar Cells

Presented by,Dawn John Mullassery, UBCPerovskite Solar Cells

OutlineIntroductionHistory and EvolutionFabrication Physics, Chemistry and NumbersFeaturesDrawbacksFuture

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

The Numbers!

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

CharacteristicsCdTeCIGSC - SiPerovskitesRaw Material CostLowMediumLowLowFinished Material costLowHighHighLowFabrication CostMediumMediumHighLowEnergy Payback PeriodMediumHighHighLowEfficiencyMediumMediumHighHigh

PerovskiteAny material with a similar structure of CaTiO3

Naturally occurring Perovskite structure.

Solar Perovskite MethylAmmonium Lead Halide (MAPbX)

History Ural MountainsofRussiabyGustav Rosenamed 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

Crystal Structure - CH3NH3PbI3A perspective of mesoscopic solar cells based on metal chalcogenide quantum dots and organometal-halide perovskites - Jae HuiRhee, Chih-ChunChungand Eric Wei-GuangDiau - NPG Asia Materials(2013)5, e68; doi:10.1038/am.2013.53

Evolution of PerovskitesJ. Phys. Chem. Lett. 2013, 4, 36233630

Evolution of Perovskites

J. Phys. Chem. C,2014,118(11), pp 56155625DOI:10.1021/jp409025w

FabricationGlassFTOTiO2Perovskite MaterialSpiro- OmeTAD

Electrons

Holes

Nature. 2013, 499, 316

Video Courtesy - CEN online

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/met6010021GOLDHTMPerovskiteTiO2 F T O

DOI: 10.1002/pip.

1.8 eV1.45 eV1.6 eV

Strong AbsorptionDOI: 10.1038/NPHOTON.2014.134

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

Bandgap Tuning - Alloying

MAPb(I1xBrx)3DOI:10.1039/C4EE00942H, Energy Environ. Sci., 2014,7, 2448-2463, and Chem. Sci., 2015,6, 613-617

J. Phys. Chem. Lett. 2014, 5, 16281635

DrawbacksStabilityLeadOnly ambient-condition results

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 C for all measurements.

YANG ET AL, ACSnano VOL. 9 NO. 2 19551963 2015

StabilityThe 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.

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 iodideFilms 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

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 the bottom.

DOI:10.1039/C5TA03577E, J. Mater. Chem. A, 2015,3, 16097-16103

Future is bright!High efficiency valuesGood photovoltaic propertiesStability is an issue Pb also!Tandem Solar Cells Hitting 40 to 50 % theoretical efficiency!R&D needed

Thank You