Efficiency Enhancement of 39% in Perovskite Solar Cells Employing ...
Prominent Efficiency Enhancement in Perovskite Solar Cells Employing Silica-Coated Gold Nanorods Runsheng Wu,†,§ Bingchu Yang,*, † Chujun Zhang,† Yulan Huang,† Yanxia Cui,*, ‡ Peng Liu,† Conghua Zhou,† Yuying Hao,‡ Yongli Gao,†,// and Junliang Yang*, † †
Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China
‡
Key Laboratory of Advanced Transducers and Intelligent Control System (Ministry of
Education), Taiyuan University of Technology, Taiyuan 030024, China §
School of New Energy Science and Engineering, Xinyu University, Xinyu 338004,
China //
Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627,
USA
*Corresponding author email: [email protected] (B. C. Yang), Telephone: +86-731-88879525 [email protected] (Y. X. Cui), Telephone: +86-351-6018862 [email protected] (J. L. Yang), Telephone: +86-731-88660256
S1
5.6 nm
(a)
10μm 5μm
-11.2 nm Conductive adhesive
(b)
Au@SiO2 PEDOT:PSS
500nm Fig. S1. AFM (a) and cross-section SEM (b) image of Au@SiO2 on the top of PEDOT:PSS layer. The Au@SiO2 nanorod clusters are distributed like the branches on the PEDOT:PSS layer.
S2
(a) Al PCBM Perovskite PEDOT:PSS ITO
500nm
(b) Al PCBM Perovskite Au@SiO2 PEDOT:PSS
500nm
ITO
Fig. S2. The cross-section SEM image of PHJ-PSC devices without (a) and with (b) Au@SiO2 nanorods. Both kinds of PHJ-PSC devices exhibit well-defined layer-by-layer configuration, and the Au@SiO2 nanorod clusters are embedded at the interface between the PEDOT:PSS layer and the perovskite layer.
S3
200
Z''()
150
With Au@SiO2 Nanorods for Different DC bias 0.3V 0.5V 0.7V fitting line
(a)
100
50
0 0
Z''()
80
50
100
Z'()
150
200
Without Au@SiO2 Nanorods for Different DC bias 0.3V 0.5V 0.7V fitting line
60
(b)
40 20 0 0
20
40
60
80
Z'()
100
120
140
Fig. S3. Nyquist plot of PHJ-PSC devices with (a) and without (b) Au@SiO2 nanorods at DC bias of 0.3 V, 0.5V and 0.7V under 1 sun illumination. Symbols are experimental data, and the solid lines correspond to the fitting lines using the equivalent circuit in (c).
S4
In Fig. S3, the high frequency is ascribed to the series resistance Rs and lower frequency involves transport resistance Rtr as well as low frequency is attributed to the recombination resistance Rrec.1-3 The equivalent circuit is used in Fig S3(c), which is consistent with published report on PSCs device.4-5 The transport resistance Rtr involves selective contacts or interface contacts with perovskite CH3NH3PbI3 film layer.1-3 Herein, we only consider the impact at the interface between the PEDOT:PSS layer and the perovskite layer because the other interfaces are essentially identical in both devices. The Rtr is shown in the Fig. S4. It is found the Rtr of PHJ-PSC devices with Au@SiO2 nanorods is larger than that of PHJ-PSC devices without Au@SiO2 nanorods. It can be attributed to the increase in contact interface duo to the incorporating of Au@SiO2 nanorods on the PEDOT:PSS layer. The increase in Rrec and the decrease in Rs compensate the unfavorable factors of increase in Rtr, leading to the
improvement
in
photovoltaic
performance,
suggesting
controlling
the
concentration of Au@SiO2 nanorods can be a key factor for PHJ-PSC devices with Au@SiO2 nanorods.
With Au@SiO2 Without Au@SiO2
1000
2
Rtr(cm )
100 10 1 0.1 0.01 0.0
0.2
0.4
0.6
0.8
1.0
Vapp(V) Fig. S4. The transport resistance of charge for PHJ-PSC devices with and without Au@SiO2 nanorods. S5
Simulation of Electric Field Distribution The simulation of electric field distribution was carried out by the finite element method. The measured thickness of each functional layer was set in the simulation. The geometrical sizes of the Au nanorods are those derived from the TEM diagram. The refractive indices of organic functional layers are measured from the ellipsometer except the perovskite film which is obtained from Ref. 6 The refractive indices of gold are from the Palik's optical constant book. The simulations were done in a square unit cell with 250 nm side length aiming for exploring the surface plasmon resonance of one or dual Au nanorods at the specific wavelengths.
Reference
(1) Boix, P.; Larramona, G.; Jacob, A.; Delatouche, B.; Mora-Sero, I.; Bisquert. J. Hole transport and recombination in all-solid Sb2S3-sensitized TiO2 solar cells using CuSCN as hole transporter. J. Phys. Chem. C 2012, 116, 1579-1587. (2) Gonzalez-Pedro, V.; Juarez-Perez, E.; Arsyad, W.; Barea, E.; Fabregat-Santiago, F.; Mora-Sero, I.; Bisquert, J. General working principles of CH3NH3PbX3 perovskite solar cells. Nano Lett. 2014, 14, 888-893. (3) Kim, H.; Mora-Sero, I.; Gonzalez-Pedro, V.; Fabregat-Santiago, F.; Juarez-Perez, E.; Park, N.; Bisquert, J. Mechanism of carrier accumulation in perovskite thinabsorber solar cells, Nat Commun. 2013, 4, 2242-2248. (4) Rong, Y.; Ku, Z.; Mei, A.; Liu, T.; Xu, M.; Ko, S.; Li, X.; Han, H.; Hole-Conductor-Free Mesoscopic TiO2/CH3NH3PbI3. Heterpjunction solar cells based on anatase nanosheets and carbon counter, J. Phys. Chem. Lett. 2014, 5, 2160-2164. (5) Liu, D.; Yang, J.; and Kelly, T. L. Compact layer free perovskite solar cells with 13.5% Efficiency, J. Am. Chem. Soc. 2014, 136, 17116-17122. (6) Löper, P.; Stuckelberger, M.; Niesen, B.; Werner, J.; Filipič, M.; Moon, S.; Yum, J.; S6
Topič, M.; Wolf, S. D.; Ballif, C. Complex refractive index spectra of CH3NH3PbI3 perovskite thin films determined by spectroscopic ellipsometry and spectrophotometry. J. Phys. Chem. Lett. 2015, 6, 66-71.
S7
Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China
‡
Key Laboratory of Advanced Transducers and Intelligent Control System (Ministry of
Education), Taiyuan University of Technology, Taiyuan 030024, China §
School of New Energy Science and Engineering, Xinyu University, Xinyu 338004,
China //
Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627,
USA
*Corresponding author email: [email protected] (B. C. Yang), Telephone: +86-731-88879525 [email protected] (Y. X. Cui), Telephone: +86-351-6018862 [email protected] (J. L. Yang), Telephone: +86-731-88660256
S1
5.6 nm
(a)
10μm 5μm
-11.2 nm Conductive adhesive
(b)
Au@SiO2 PEDOT:PSS
500nm Fig. S1. AFM (a) and cross-section SEM (b) image of Au@SiO2 on the top of PEDOT:PSS layer. The Au@SiO2 nanorod clusters are distributed like the branches on the PEDOT:PSS layer.
S2
(a) Al PCBM Perovskite PEDOT:PSS ITO
500nm
(b) Al PCBM Perovskite Au@SiO2 PEDOT:PSS
500nm
ITO
Fig. S2. The cross-section SEM image of PHJ-PSC devices without (a) and with (b) Au@SiO2 nanorods. Both kinds of PHJ-PSC devices exhibit well-defined layer-by-layer configuration, and the Au@SiO2 nanorod clusters are embedded at the interface between the PEDOT:PSS layer and the perovskite layer.
S3
200
Z''()
150
With Au@SiO2 Nanorods for Different DC bias 0.3V 0.5V 0.7V fitting line
(a)
100
50
0 0
Z''()
80
50
100
Z'()
150
200
Without Au@SiO2 Nanorods for Different DC bias 0.3V 0.5V 0.7V fitting line
60
(b)
40 20 0 0
20
40
60
80
Z'()
100
120
140
Fig. S3. Nyquist plot of PHJ-PSC devices with (a) and without (b) Au@SiO2 nanorods at DC bias of 0.3 V, 0.5V and 0.7V under 1 sun illumination. Symbols are experimental data, and the solid lines correspond to the fitting lines using the equivalent circuit in (c).
S4
In Fig. S3, the high frequency is ascribed to the series resistance Rs and lower frequency involves transport resistance Rtr as well as low frequency is attributed to the recombination resistance Rrec.1-3 The equivalent circuit is used in Fig S3(c), which is consistent with published report on PSCs device.4-5 The transport resistance Rtr involves selective contacts or interface contacts with perovskite CH3NH3PbI3 film layer.1-3 Herein, we only consider the impact at the interface between the PEDOT:PSS layer and the perovskite layer because the other interfaces are essentially identical in both devices. The Rtr is shown in the Fig. S4. It is found the Rtr of PHJ-PSC devices with Au@SiO2 nanorods is larger than that of PHJ-PSC devices without Au@SiO2 nanorods. It can be attributed to the increase in contact interface duo to the incorporating of Au@SiO2 nanorods on the PEDOT:PSS layer. The increase in Rrec and the decrease in Rs compensate the unfavorable factors of increase in Rtr, leading to the
improvement
in
photovoltaic
performance,
suggesting
controlling
the
concentration of Au@SiO2 nanorods can be a key factor for PHJ-PSC devices with Au@SiO2 nanorods.
With Au@SiO2 Without Au@SiO2
1000
2
Rtr(cm )
100 10 1 0.1 0.01 0.0
0.2
0.4
0.6
0.8
1.0
Vapp(V) Fig. S4. The transport resistance of charge for PHJ-PSC devices with and without Au@SiO2 nanorods. S5
Simulation of Electric Field Distribution The simulation of electric field distribution was carried out by the finite element method. The measured thickness of each functional layer was set in the simulation. The geometrical sizes of the Au nanorods are those derived from the TEM diagram. The refractive indices of organic functional layers are measured from the ellipsometer except the perovskite film which is obtained from Ref. 6 The refractive indices of gold are from the Palik's optical constant book. The simulations were done in a square unit cell with 250 nm side length aiming for exploring the surface plasmon resonance of one or dual Au nanorods at the specific wavelengths.
Reference
(1) Boix, P.; Larramona, G.; Jacob, A.; Delatouche, B.; Mora-Sero, I.; Bisquert. J. Hole transport and recombination in all-solid Sb2S3-sensitized TiO2 solar cells using CuSCN as hole transporter. J. Phys. Chem. C 2012, 116, 1579-1587. (2) Gonzalez-Pedro, V.; Juarez-Perez, E.; Arsyad, W.; Barea, E.; Fabregat-Santiago, F.; Mora-Sero, I.; Bisquert, J. General working principles of CH3NH3PbX3 perovskite solar cells. Nano Lett. 2014, 14, 888-893. (3) Kim, H.; Mora-Sero, I.; Gonzalez-Pedro, V.; Fabregat-Santiago, F.; Juarez-Perez, E.; Park, N.; Bisquert, J. Mechanism of carrier accumulation in perovskite thinabsorber solar cells, Nat Commun. 2013, 4, 2242-2248. (4) Rong, Y.; Ku, Z.; Mei, A.; Liu, T.; Xu, M.; Ko, S.; Li, X.; Han, H.; Hole-Conductor-Free Mesoscopic TiO2/CH3NH3PbI3. Heterpjunction solar cells based on anatase nanosheets and carbon counter, J. Phys. Chem. Lett. 2014, 5, 2160-2164. (5) Liu, D.; Yang, J.; and Kelly, T. L. Compact layer free perovskite solar cells with 13.5% Efficiency, J. Am. Chem. Soc. 2014, 136, 17116-17122. (6) Löper, P.; Stuckelberger, M.; Niesen, B.; Werner, J.; Filipič, M.; Moon, S.; Yum, J.; S6
Topič, M.; Wolf, S. D.; Ballif, C. Complex refractive index spectra of CH3NH3PbI3 perovskite thin films determined by spectroscopic ellipsometry and spectrophotometry. J. Phys. Chem. Lett. 2015, 6, 66-71.
S7
