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Solar cell efficiencies

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Solar cell efficiencies

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Structure of (MA)PbI3 (MA = [CH3NH3]+)

Perovskite Structure

Halide perovskites: ABX3

4

Structure of (MA)PbI3 (MA = [CH3NH3]+)

Perovskite Structure

Halide perovskites: ABX3

A-site cations: Rb+, Cs+, [CH3NH3]+, [(NH2)2CH]+

A site

5

Structure of (MA)PbI3 (MA = [CH3NH3]+)

Perovskite Structure

Halide perovskites: ABX3

B-site cations: Mn2+, Cd2+, Cu2+, Sn2+, Ge2+,Pb2+

A-site cations: Rb+, Cs+, [CH3NH3]+, [(NH2)2CH]+

A site B site

6

CNN. Published Jan. 22nd, 2016

Lead Toxicity

7

CNN. Published Jan. 22nd, 2016

Lead Toxicity

8

The only level of lead exposure not detrimental to human health is zero.

CNN. Published Jan. 22nd, 2016

Lead Toxicity

9

The only level of lead exposure not detrimental to human health is zero.

620 mg of PbI2 can dissolve in 1 L of water

CNN. Published Jan. 22nd, 2016

Lead Toxicity

10

The only level of lead exposure not detrimental to human health is zero.

620 mg of PbI2 can dissolve in 1 L of water

Systems to prevent lead exposure must be completely fail-safe.

Build a better perovskite

Reduce Toxicity

11

Preserve 1.6 eV band gap

Deposition of films from solution

Defect tolerance

Build a better perovskite

Reduce Toxicity

12

Preserve 1.6 eV band gap

Deposition of films from solution

Defect tolerance

Build a better perovskite

Reduce Toxicity

The lead perovskite electronic structure is key!

13

Lead-halide perovskite band structure

Valence Band

Conduction Band

Eg

Halide p orbitals +

Pb s orbitals

Pb p orbitals

Lead-halide perovskite band structure

Valence Band

Conduction Band

Eg

Pb 82

207.2

Halide p orbitals +

Pb s orbitals

Pb p orbitals

Lead-halide perovskite band structure

Valence Band

Conduction Band

Eg

Pb 82

207.2

Pb2+ electronic configuration:

[Xe] 4f14 5d10 6s2 6p0

Halide p orbitals +

Pb s orbitals

Pb p orbitals

A brief jaunt around the periodic table

17

A brief jaunt around the periodic table

18

Hao, Stoumpos, Cao, Chang, Kanatzidis. Nature Photon. (2014) 8, 489. Noel, Stranks, Herz, Snaith, et al. Energy Environ. Sci. (2014) 7, 3061.

A brief jaunt around the periodic table

19

Hao, Stoumpos, Cao, Chang, Kanatzidis. Nature Photon. (2014) 8, 489. Noel, Stranks, Herz, Snaith, et al. Energy Environ. Sci. (2014) 7, 3061.

A brief jaunt around the periodic table

20

Hao, Stoumpos, Cao, Chang, Kanatzidis. Nature Photon. (2014) 8, 489. Noel, Stranks, Herz, Snaith, et al. Energy Environ. Sci. (2014) 7, 3061.

A brief jaunt around the periodic table

21

Hao, Stoumpos, Cao, Chang, Kanatzidis. Nature Photon. (2014) 8, 489. Noel, Stranks, Herz, Snaith, et al. Energy Environ. Sci. (2014) 7, 3061.

A brief jaunt around the periodic table

22

Hao, Stoumpos, Cao, Chang, Kanatzidis. Nature Photon. (2014) 8, 489. Noel, Stranks, Herz, Snaith, et al. Energy Environ. Sci. (2014) 7, 3061.

Double Perovskites (Elpasolites)

23

ABX3

Double Perovskites (Elpasolites)

24

A2BB’X6 ABX3

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138. Cs2AgBiBr6

Cs2AgBiBr6

Double Perovskites (Elpasolites)

25

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138. Cs2AgBiBr6

Cs2AgBiBr6

Double Perovskites (Elpasolites)

26

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138. Cs2AgBiBr6

Cs2AgBiBr6

Double Perovskites (Elpasolites)

27

McClure, Ball, Windl, Woodward. Chem. Mater. (2016) 28, 1348. Cs2AgBiBr6 / Cs2AgBiCl6

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138. Cs2AgBiBr6

Cs2AgBiBr6

Double Perovskites (Elpasolites)

28

McClure, Ball, Windl, Woodward. Chem. Mater. (2016) 28, 1348. Cs2AgBiBr6 / Cs2AgBiCl6

Volonakis, Filip, Snaith, Giustino, et al. J. Phys. Chem. Lett. (2016) 7, 1254. Cs2AgBiCl6

Wei, Deng, Bristowe, Cheetham, et al. Mater. Horiz. (2016) 3, 328. (MA)2KBiCl6

Deng, Wei, Cheetham, Bristowe, et al. J. Mater. Chem. A (2016) 4, 12025. (MA)2TlBiCl6

29

Optical Properties

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

30

Optical Properties

VB

CB Direct

Strong absorption

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

31

Optical Properties

VB

CB Direct

Strong absorption

Indirect VB

CB

Weak absorption

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

32

Optical Properties

Eg (indirect) = 1.95 eV

VB

CB Direct

Strong absorption

Indirect VB

CB

Weak absorption

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

Time-resolved photoluminescence

33

𝐼 𝑡 ∝ ∆𝑛(𝑡)

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

Time-resolved photoluminescence

34

𝐼 𝑡 = 𝐴 ∗ 𝑒−𝑡 𝜏⁄

𝐼 𝑡 ∝ ∆𝑛(𝑡)

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

Time-resolved photoluminescence

35

𝐼 𝑡 = 𝐴 ∗ 𝑒−𝑡 𝜏⁄

𝐼 𝑡 ∝ ∆𝑛(𝑡)

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

Time-resolved photoluminescence

36 Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

𝐼 𝑡 = 𝐴 ∗ 𝑒−𝑡 𝜏⁄

𝐼 𝑡 ∝ ∆𝑛(𝑡)

Material Stability

37 Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

* = PbI2

Smith, Hoke, Solis-Ibarra, McGehee, Karunadasa. Angew. Chem. Int. Ed. (2014) 53, 11232

(MA)PbI3

Material Stability

38 Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

* = PbI2

Smith, Hoke, Solis-Ibarra, McGehee, Karunadasa. Angew. Chem. Int. Ed. (2014) 53, 11232

(MA)PbI3 Cs2AgBiBr6

39

Material Stability: Heat

| | | | | | | | | | | | | | | | | = PbBr2 / PbI2

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

40

Material Stability: Heat

| | | | | | | | | | | | | | | |

| | |

|

| |

| = PbBr2 / PbI2

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

41

Material Stability: Heat

| | | | | | | | | | | | | | | |

| | |

|

| |

| = PbBr2 / PbI2

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

Summary

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

Cs2AgBiBr6

42

Summary

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

Cs2AgBiBr6

43

• First bismuth bromide perovskite

• Low toxicity • Moisture/heat resistant • Long carrier lifetimes

(660 ns)

Summary

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

Cs2AgBiBr6

44

• First bismuth bromide perovskite

• Low toxicity • Moisture/heat resistant • Long carrier lifetimes

(660 ns) • Large band gap (1.95 eV) • Indirect band gap

Summary

Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

Cs2AgBiBr6

45

• First bismuth bromide perovskite

• Low toxicity • Moisture/heat resistant • Long carrier lifetimes

(660 ns) • Large band gap (1.95 eV) • Indirect band gap

Double perovskites expand scope of halide perovskites beyond 2+ metals to include 1+ − 4+ metals at the B site.

Acknowledgments

Te Hu and Prof. Aaron Lindenberg Stanford Graduate Fellowship (SGF)

The Karunadasa Group!

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1.83 eV

Ephoton + Ephonon

1.83 eV

Ephoton + Ephonon

2.07 eV

Ephoton − Ephonon

Optical Properties

Ephoton

Ephonon

Ephoton

Ephonon

Edirect

Eg (indirect) = 1.95 eV

47 Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.

CB

VB

Time-resolved photoluminescence

48 Slavney, Hu, Lindenberg, Karunadasa. J. Am. Chem. Soc. (2016) 138, 2138.