Solar cell efficiencies
2
Solar cell efficiencies
3
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!
46
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.