Silicon Tandem Module Design on Hot-Spot

ACS Paragon Plus Environment. ACS Applied Energy Materials. 1. 2. 3. 4. 5. 6. 7. 8. 9 ... 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. ...
0 downloads 0 Views 2MB Size
Subscriber access provided by Kaohsiung Medical University

Letter

The Impact of Perovskite/Silicon Tandem Module Design on Hot-Spot Temperature Jiadong Qian, Andrew F. Thomson, Yiliang Wu, Klaus Weber, and Andrew W. Blakers ACS Appl. Energy Mater., Just Accepted Manuscript • DOI: 10.1021/acsaem.8b00480 • Publication Date (Web): 14 Jun 2018 Downloaded from http://pubs.acs.org on June 14, 2018

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Energy Materials

The Impact of Perovskite/Silicon Tandem Module Design on Hot-Spot Temperature Jiadong Qian*, Andrew F. Thomson, Yiliang Wu, Klaus J. Weber and Andrew W. Blakers* Australian National University, Canberra, ACT 0200 Australia Corresponding Author *[email protected] *[email protected] Notes The authors declare no competing financial interest. Keywords tandem cells, perovskite, silicon, solar modules, hot spots, mismatch, partial shading

ACS Paragon Plus Environment

1

ACS Applied Energy Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 22

ABSTRACT Organic-inorganic hybrid perovskite materials, as promising candidates for highefficiency silicon-based tandem solar cells, have passed reliability test at 85 °C for 1,000 hours. However, silicon photovoltaic modules experience elevated temperatures under fault operating conditions. We propose and simulate tandem modules using 2- and 4-terminal tandem cells and show potential detrimental temperatures under realistic shading conditions. A module using series-connected 2-terminal cells reaches 207 °C compared to 137° C for 4-terminal cells from simulation. The cell temperature can be reduced with interdigitated-back-contact cells, additional bypass diodes or silicon half-cell configurations.

ACS Paragon Plus Environment

2

Page 3 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Energy Materials

Solar cells made of perovskite materials were originally reported by Kojima el al. with a power conversion efficiency of 3.8%1. With a bandgap greater than 1.5 eV, organic-inorganic hybrid perovskite solar cells (PSC) are promising candidates for use as the top cell in tandem with silicon (Si) bottom cells. With suitable bandgap tuning, such a design allows for a theoretical efficiency of 40%2,3. Efficiencies of 23.6%4 and 26.7%5 have been achieved for 2-terminal (2T) and 4-terminal (4T) designs respectively. Although PSCs have been reported with the ability to withstand damp heat exposure (85 °C, 85% relative humidity)6, the long-term performance stability of perovskite cells under real operational temperatures in the field is of concern. High temperature has a critical impact on the stability of PSC/Si tandem devices. The currently most-used absorber for high-efficiency PSCs, methyl-ammonium-lead-iodide (MAPbI3), starts to decompose between 234 °C and 300 °C7,8. The low thermal conductivity of MAPbI3 may cause thermal stress at high temperature and accelerate the PSC degradation9. High cell temperature also makes it more challenging for organic hole-transport materials selection as the two materials used for current high-efficiency PSCs, 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9-9′-spirobifluorene (spiro-OMeTAD) and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), are known to degrade above 90 °C6,10. Some organic semiconductors11 and p-type inorganic materials such as Copper (I) thiocyanate (CuSCN)12 are demonstrated to have improved thermal stability up to 125 °C. It has been shown that besides the impact on the material stability, temperatures above 100 °C could cause interfacial degradation6. Additionally, most 2T high-efficiency tandem cells use silicon heterojunction solar cells for the bottom cell, which have poor thermal stability beyond 200 °C13. In practice, the cells in silicon photovoltaic (PV) modules sometimes must, and can, operate at temperatures > 100 °C when a significant cell current mismatch occurs leading to reverse-bias

ACS Paragon Plus Environment

3

ACS Applied Energy Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 22

induced hot spots14. The hot spots in cell strings occur when the maximum current generation capacity of a cell/cells is less than the operating current in the string. Such cell current reduction is commonly caused by partial shading, solder de-bonding and cell cracks. Weak cells are reverse biased to allow them to match the string current, and therefore dissipate heat. A hot-spot temperature of 312 °C has been observed on a commercial crystalline-silicon (c-Si) module at short-circuit15, and hot spots are ranked among the most important failure modes for Si PV modules16-18. Experiments on thin-film modules show a permanent power loss between 4% and 14% at realistic shading conditions18. The impact of reverse-bias on PSCs has been investigated by Bowring et al.19 showing a loss of efficiency from local shunt formation and open-circuit voltage (Voc) reduction. However, a module-level modelling on the hot spot effect in perovskite/silicon tandem modules is yet to be conducted. This paper discusses the impact on perovskite/silicon tandem module of elevated temperature arising from cell current mismatch caused by fault conditions. We present plausible tandem module designs, based on the conventional Si module design for the 2T module, and a blend of conventional Si module and thin-film module designs for the 4T module. With these two modules designs, we simulate the cell temperatures caused by hot spots. Further, module design strategies are discussed to reduce the cell temperatures during shading events.

ACS Paragon Plus Environment

4

Page 5 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Energy Materials

Figure 1. Cell shapes and connection configurations for (a) 2T and (b) 4T PSC/Si tandem-cell modules. The cell connection configurations for 2T and 4T tandem-cell module developed in this work are illustrated in Figure 1. The 2T module in (a) consists of 72 series-connected tandem cells. Each tandem cell in the 2T module is comprised of a perovskite cell monolithically grown on a Si cell, both with an identical cell size of 15.6 cm × 15.6 cm. The 72-cell module design was used as it is rapidly becoming the industry standard20. The 4T module in (b) is formed with an interconnected perovskite cell layer mechanically stacked on, and in thermal contact with, a Si cell layer. Similar to the 2T design, the Si layer is made of 72 series-connected Si cells with a size of 15.6 cm × 15.6 cm. The perovskite layer consists of 48 cell strips, maintaining a similar operating voltage with the Si layer. Each cell has a size of 191.6 cm × 2 cm and aligns with the long edge of the module. Therefore the area of a perovskite cell strip overlapping one silicon cell is less than 1/12 of the perovskite cell area. Three bypass diodes are connected in parallel with three cell strings each consisting of 24 series-connected tandem cells in the 2T module. The same bypass diode configuration is implemented in the Si cell layer in the 4-terminal module. Figure

ACS Paragon Plus Environment

5

ACS Applied Energy Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 22

S3 shows the effect of a bypass diode on the series-connected cell string where one cell is reverse biased by shading. The reverse bias at the shaded cell is limited so that the total voltage of the string does not drop below the bypass diode activation voltage, which is approximately 0.33 V.21 Current generation mismatch in stringed cells can be caused by a number of effects such as shading and cell defects. In this work, we assume there is an event, referred as shading for brevity, affecting one cell in the string that causes current generation mismatch. The shading ratio of the cell for which light is blocked is represented by a reduction in the shaded cell’s shortcircuit current. Two types of silicon cell with differing reverse-bias behaviour are modelled in the 4T module, namely mono c-Si cells (conventional module) and interdigitated back contact (IBC) Si cells (IBC module). Mono c-Si cells have low reverse breakdown current22 while IBC cells have a soft breakdown at low reverse bias23 (as in Figure S2). Hence, IBC cells generate lower heat under partial shading24. For the 2T cells, the reverse-bias behaviour of the Si cell is assumed to be akin to mono c-Si cells with minimal reverse leakage current. This assumption provides the lowest heat dissipation and cell temperature using front-emitter bottom cells. The simulated module IV curves and operating points are shown in Figure. 2 (a) for the three tandem modules and a reference module comprising 72 series-connected conventional Si cells when a shading area equivalent to 20% of a single Si cell is applied in each module. The operating current marked by dashed lines is imposed externally by the operating current of a string of modules. Figure. 2 (b) shows the cell IV diagrams and operating points for each reversebiased cell in the four modules. The bypass diodes in the Si and 4T conventional modules activate and limit the reverse bias at the shaded cells.25

ACS Paragon Plus Environment

6

Page 7 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Energy Materials

Figure 2 (a) Module IV curves when 20% of a Si cell is shaded, with the operating points marked by dots and determined by fixed externally-imposed operating current (Iop), (b) IV curves of reverse-biased cells (negative voltage) in the simulated modules, with the operating conditions marked by dots. Aggregate heat dissipation intensity including the heat generation from reverse-biased cells and the residual heat from incident light, is depicted in Figure 3 (a) for 12 simulated shading conditions from 0% to 100%. The operating voltage and current of all reverse biased cells are provided in Figure S5. The 2T module has the highest heat dissipation intensity with the shaded perovskite and Si cells both reverse biased. Due to the high string voltages, the shaded Si cell in the 2T module is reverse biased by > 25 V for all shading ratios ≥ 10%. The maximum reverse

ACS Paragon Plus Environment

7

ACS Applied Energy Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 22

bias across the shaded Si cell is 16.3 V in the 4T conventional module, 2.7 V in the 4T IBC module and 14.9 V in the reference Si module at 15% shading. In the two 4T modules, the shape and size difference between the perovskite and Si cells restrict the shade impact on the Isc of the perovskite cell to less than 1/12. The reduced Isc remains higher than Iop (4.0 A). Therefore, only the Si cells are reverse biased generating heat in the 4T modules. Benefiting from the perovskite filter above the Si cell layer, the current density at the Si cells in the 4T modules is approximately halved compared with the reference Si module, which reduces the heat dissipation. The “leaky” reverse current of IBC cells allows sufficient current to flow to compensate for the reduced Isc without reverse biasing the entire string, thus helping to maintain even lower heat dissipation. The use of IBC cells in a 4T tandem-cell module prevent the activation of bypass diodes even when a Si cell is fully shaded, thus removing the need for bypass diodes. A line shadow along the long edge of the module that leads to reverse bias at both the perovskite and Si cells in the 4T module is presented in Figure S6. The simulated operating conditions of a perovskite cell under shading and the heat dissipation intensity are simulated and depicted in Figure S7 and Figure S8. The total heat dissipation intensity from the perovskite cell and the Si cell in the 4T conventional module is substantially lower from a line shadow compared with the worst case from the applied shade investigated. Whereas in the 4T IBC module, the heat dissipation from the perovskite cell is more significant as the heat from the IBC cell is much lower. The simulated perovskite cell temperatures in the three tandem-cell modules and the Si cell temperatures in the reference Si module are presented in Figure 3 (b) for the same shading conditions used in the heat dissipation simulation. The cells in all simulated modules were assumed to be encapsulated with the polymer material, ethylene vinyl acetate (EVA), and then

ACS Paragon Plus Environment

8

Page 9 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Energy Materials

covered by glass on both sides as illustrated in Figure S4. A simplified one-dimensional thermal model26 was used with the assumption of uniform heat dissipation and negligible lateral heat conduction across the perovskite cell strips in the 4T module, EVA encapsulation and glass layers. The equations used for the thermal simulation are presented in the Supporting Information. More complex three-dimensional thermal modelling for hot-spot PV modules has been demonstrated in other literature27 that would achieve a spatially resolved result. Here we provide a baseline comparison of the hot-spot temperatures between different module configurations without considering the impact of inhomogeneous reverse breakdown due to local shunts. The heat dissipation calculation and thermal simulation method have been verified in literature.26,27 The simulated temperatures follow similar trends of the heat dissipation. The PSC temperature in the 2T module peaks at 207 °C when a cell is shaded by 30% and remains high (> 170 °C) for all shading ratios ≥ 15%. This is due to the large reverse bias developed at the shaded Si cell in the 2T module driving through significant reverse leakage current that is independent with the illumination. The 4T module has lower PSC temperatures compared with the reference Si module. At the worst-case shade ratio of 15% for both 4T modules, the PSC temperature in the module using mono c-Si cells is 137 °C and is even lower at 73 °C in the IBC module. A line shadow with a size of 2.3 cm × 78.0 cm will lead to a higher PSC temperature of 116 °C due to the additional heat dissipation from the perovskite cell.

ACS Paragon Plus Environment

9

ACS Applied Energy Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 22

Figure 3 (a) Intensity of the aggregated heat dissipation from the PSC and Si cells and (b) simulated temperatures of the PSC in the 2T module and the Si cell in the 4T conventional module, the 4T IBC module, and the Si module. The peak temperatures simulated in the 2T tandem module and the 4T conventional module both exceed the critical temperature for the decomposition of the two aforementioned hole-transport materials (spiro-OMeTAD and PTAA) and the interfacial degradation in the PSC. The use of IBC cells in the 4T devices substantially reduces the cell temperature to below 80 °C, making the use of such cells potentially an attractive option. However, recent work indicates that the homogeneous junction breakdown in IBC cells may have an impact on the passivation quality of the Al2O3 films28 of these cells, thereby potentially degrading their performance. Further investigation is therefore required to establish their usefulness in this application.

ACS Paragon Plus Environment

10

Page 11 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Energy Materials

Here, we introduce two design options to lower the perovskite cell temperatures under partial shading conditions on the module level. The first option is to reduce the number of cells per bypass diode. A string operates at a lower current than Imp when an included cell is shaded affecting the rest of the cells in the string that are connected with it in series. The other (illuminated) cells in the string will operate at a current lower than Imp and at a voltage between their maximum power point voltage and open circuit-voltage. The developed reverse bias at the weak cell is limited to the sum of the open circuit voltage of the rest cells in the string and VBPD. Reducing the number of cells in a string lowers the reverse bias built across the shaded cell when the bypass diode is activated, and therefore decreases the heat dissipation and the hot-spot induced cell temperature.29 Figure. 4 (a) shows impact of the number of cells per diode on the simulated worst-case temperatures for the perovskite cells in four simulated modules. When the heat dissipation from the shaded cell is voltage-restricted, fewer cells in a string significantly lowers the peak perovskite cell temperatures in the 2T module and 4T conventional module. It is worth noting that the additional bypass diodes per module may increase the electronic and wiring cost and diode failure rate, which will impact the levelized cost of electricity of the tandem module. The second option is to use laser separated half-size Si cells and series-parallel-series (SPS) cell connection.30 A half-cell module design comprised of two sets of 72 series-connected submodules that are connected in parallel was simulated with either 3 or 6-bypass diodes (Figure S9). The maximum temperatures in the 2T and 4T conventional modules are plotted in Figure 4 (b). The worst-case PSC temperature in a partially shaded 2T module drops by 21 °C to 186 °C with 3 diodes implemented, and further decreases to 134 °C in a 6-diode configuration. The 4T conventional module benefits less from the half-cell SPS design. The worst-case temperature

ACS Paragon Plus Environment

11

ACS Applied Energy Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 12 of 22

decreases to 129 °C in a a 3-diode module and is further lowered to 94 °C with 6 diodes. The temperature drops are caused by the compensated current from the parallel connected string and the higher relative shading ratio on a half-size cell for the same shading area.

Figure 4 (a) Simulated peak cell temperature for the perovskite cells with different number cells per bypass diode. (b) Temperature decrease by using half-size silicon cells with a series-parallelseries configuration for 3- and 6-diode configurations. In summary, the PSC temperatures in three proposed tandem-cell modules including a 2T module and two 4T modules using mono crystalline and IBC Si cells were simulated at multiple shading conditions. The module design with 72 series-connected 2T tandem cells and 3 bypass diodes is found to have the highest PSC temperatures of 207 °C. The 4T conventional modules exhibit lower heat dissipation and cell temperatures (137 °C) than the reference Si module. By

ACS Paragon Plus Environment

12

Page 13 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Energy Materials

using IBC cells as the bottom cell in the 4T module, the perovskite cell temperature at the worstcase shading condition is reduced to 116 °C, and the need of using bypass diodes is waived. Two potential design options are suggested to mitigate the impact of the hot spot effect, including fewer cells per bypass diodes and using a module design with half-cut cells and series-parallelseries cell connections.

ASSOCIATED CONTENT Supporting Information. The following files are available free of charge. Simulation method, simulated cell operating conditions and half-cell configuration schematic diagram (PDF) AUTHOR INFORMATION Corresponding Author *E-mail: [email protected] *E-mail: [email protected] Funding Sources This work was funded in part by the Australian Renewable Energy Agency through Grant 2014/RND008. J.Q. REFERENCES

ACS Paragon Plus Environment

13

ACS Applied Energy Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 22

(1) Kojima, A.; Teshima, K.; Shirai, Y.; Miyasaka, T., Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells. J. Am. Chem. Soc. 2009, 131, 60506051. (2) Vos, A. D., Detailed Balance Limit of the Efficiency of Tandem Solar Cells. J. Phys. D: Appl. Phys. 1980, 13, 839–846. (3) Rühle, S., The Detailed Balance Limit of Perovskite/Silicon and Perovskite/CdTe Tandem Solar Cells. Phys. Status Solidi A 2017, 214, 1600955-n/a. (4) Bush, K. A.; Palmstrom, A. F.; Yu, Z. J.; Boccard, M.; Cheacharoen, R.; Mailoa, J. P.; McMeekin, D. P.; Hoye, R. L. Z.; Bailie, C. D.; Leijtens, T.; Peters, I. M.; Minichetti, M. C.; Rolston, N.; Prasanna, R.; Sofia, S.; Harwood, D.; Ma, W.; Moghadam, F.; Snaith, H. J.; Buonassisi, T.; Holman, Z. C.; Bent, S. F.; McGehee, M. D., 23.6%Efficient Monolithic Perovskite/Silicon Tandem Solar Cells with Improved Stability. Nat. Energy 2017, 2, 17009. (5) Ramirez Q.; Cesar, O.; Shen, Y.; Salvador, M.; Forberich, K.; Schrenker, N.; Spyropoulos, G. D.; Heumuller, T.; Wilkinson, B.; Kirchartz, T.; Spiecker, E.; Verlinden, P.; Zhang, X.; Green, M.; Ho-Baillie, A.; Brabec, C. J., Balancing electrical and optical losses for efficient 4-terminal Si-perovskite solar cells with solution processed percolation electrodes. J. Mater. Chem. A, 2018, 6, 3583-3592. (6) Kim, Y. C.; Yang, T. Y.; Jeon, N. J.; Im, J.; Jang, S.; Shin, T. J.; Shin, H. W.; Kim, S.; Lee, E.; Kim, S; Noh, J. H.; Seok, S. I.; Seo, J., Engineering Interface Structures Between Lead Halide Perovskite and Copper Phthalocyanine for Efficient and Stable Perovskite Solar Cells. Energy Environ. Sci. 2017, 10, 2109–2116.

ACS Paragon Plus Environment

14

Page 15 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Energy Materials

(7) Dualeh, A.; Gao, P.; Seok, S. I.; Nazeeruddin, M. K.; Grätzel, M., Thermal Behavior of Methylammonium Lead-Trihalide Perovskite Photovoltaic Light Harvesters. Chem. Mater. 2014, 26, 6160-6164. (8) Conings, B.; Drijkoningen, J.; Gauquelin, N.; Babayigit, A.; D'Haen, J.; D'Olieslaeger, L.; Ethirajan, A.; Verbeeck, J.; Manca, J.; Mosconi, E.; Angelis, F. D.; Boyen, H., Intrinsic Thermal Instability of Methylammonium Lead Trihalide Perovskite. Adv. Energy Mater. 2015, 5, 1500477. (9) Pisoni, A.; Jaćimović, J.; Barišić, O. S.; Spina, M.; Gaál, R.; Forró, L.; Horváth, E., Ultra-Low

Thermal

Conductivity

in

Organic–Inorganic

Hybrid

Perovskite

CH3NH3PbI3. J. Phys. Chem. Lett. 2014, 5, 2488–2492. (10)

Divitini, G.; Cacovich, S.; Matteocci, F.; Cinà, L.; Di Carlo, A.; Ducati, C., In

Situ Observation of Heat-Induced Degradation of Perovskite Solar Cells. Nat. Energy 2016, 1, 15012. (11)

Landerer, D.; Mertens, A.; Freis, D.; Droll, R.; Leonhard, T.; Schulz, A. D.; Bahro, D.;

Colsmann, A., Enhanced Thermal Stability of Organic Solar Cells Comprising Ternary D-D-A Bulk-Heterojunctions. npj Flexible Electron. 2017, 1, 11. (12)

Yu, Z.; Sun, L. Inorganic Hole‐Transporting Materials for Perovskite Solar Cells. Small

Methods 2018, 2, 1700280. (13)

Wu, Y.; Yan, D.; Peng, J.; Duong, T.; Wan, Y.; Phang, S. P.; Shen, H.; Wu, N.;

Barugkin, C.; Fu, X.; Surve, S.; Grant, D.; Walter, D.; White, T. P.; Catchpole, K. R.; Weber, K. J., Monolithic Perovskite/Silicon-Homojunction Tandem Solar Cell with Over 22% Efficiency. Energy Environ. Sci. 2017. 2472–2479

ACS Paragon Plus Environment

15

ACS Applied Energy Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(14)

Page 16 of 22

García, M. C. A.; Herrmann, W.; Böhmer, W.; Proisy, B., Thermal and Electrical

Effects Caused by Outdoor Hot-Spot Testing in Associations of Photovoltaic Cells. Prog. Photovolt: Res. Appl. 2003, 11, 293-307. (15)

Cunningham, D. W. Analysis of Hot Spots in Crystalline Silicon Modules and

their Impact on Roof Structures, PVMRW, Denver Colorado, National Renewable Energy Laboratory: Denver Colorado, 2011; p 642. (16)

Köntges, M.; Altmann, S.; Heimberg, T.; Jahn, U.; Berger, K. A. Mean

Degradation Rates In PV Systems for Various Kinds of PV Module Failures, 32nd EUPVSEC, 2016; pp 1435-1443. (17)

Shrestha, S. M.; Mallineni, J. K.; Yedidi, K. R.; Knisely, B.; Tatapudi, S.;

Kuitche, J.; TamizhMani, G., Determination of Dominant Failure Modes Using FMECA on the Field Deployed c-Si Modules Under Hot-Dry Desert Climate. IEEE J. Photovolt. 2015, 5, 174-182. (18)

Silverman, T. J.; Mansfield, L.; Repins, I.; Kurtz, S., Damage in Monolithic Thin-

Film Photovoltaic Modules Due to Partial Shade. IEEE J. Photovolt. 2016, 6, 13331338. (19)

Bowring, A. R.; Bertoluzzi, L.; O'Regan, B. C.; McGehee, M. D., Reverse Bias

Behavior of Halide Perovskite Solar Cells. Adv. Energy Mater. 2018, 8, 1702365. (20)

International Technology Roadmap for Photovoltaic (ITRPV): 2016 Results;

March 2017. [Online] Available at: http://www.itrpv.net/.cm4all/mediadb/ITRPV%20Eighth%20Edition%202017.pdf

ACS Paragon Plus Environment

16

Page 17 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Energy Materials

(21)

Vishay SMD Photovoltaic Solar Cell Protection Schottky Rectifier. 2017.

[Online] Available at: https://www.vishay.com/docs/89127/ss12p4s.pdf. (22)

Wang, E.; Wang, H.; Yang, H. Comparison of the Electrical Properties of PERC

Approach Applied to Monocrystalline and Multicrystalline Silicon Solar Cells. Int. J. Photoenergy, 2016, 2016, 1-6 (23)

Chu, H.; Koduvelikulathu, L. J.; Mihailetchi, V. D.; Galbiati, G.; Halm, A.;

Kopecek, R., Soft Breakdown Behavior of Interdigitated-back-contact Silicon Solar Cells. Energy Procedia 2015, 77, 29-35. (24)

Smith, D. D.; Cousins, P. J.; Masad, A.; Waldhauer, A.; Westerberg, S.; Johnson,

M.; Tu, X.; Dennis, T.; Harley, G.; Solomon, G.; Rim, S.; Shepherd, M.; Harrington; S.; Defensor, M.; Leygo, A.; Tomada, P.; Wu, J.; Pass, T.; Ann, L.; Smith, L.; Bergstrom, N.; Nicdao, C.; Tipones, P.; Vicente, D., Generation III High Efficiency Lower Cost Technology: Transition to Full Scale Manufacturing, 38th IEEE PVSC, 2012; pp 1594-1597. (25)

Fertig, F.; Rein, S.; Schubert, M.; Warta, W. Impact of Junction Breakdown in

Multi-Crystalline Silicon Solar Cells on Hot Spot Formation and Module Performance, 26th EUPVSEC, 2011; p 80. (26)

Notton, G.; Cristofari, C.; Mattei, M.; Poggi, P., Modelling of a Double-Glass

Photovoltaic Module Using Finite Differences. Appl. Therm. Eng. 2005, 25, 28542877.

ACS Paragon Plus Environment

17

ACS Applied Energy Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(27)

Page 18 of 22

Geisemeyer, I.; Fertig, F.; Warta, W.; Rein, S.; Schubert, M. C., Prediction of

Silicon PV Module Temperature for Hot Spots and Worst Case Partial Shading Situations Using Spatially Resolved Lock-In Thermography. Sol. Energy Mater Sol. Cells 2014, 120, Part A, 259-269. (28)

Müller, R.; Reichel, C.; Yang, X.; Richter, A.; Benick, J.; Hermle, M., Impact of

the Homogeneous Junction Breakdown in IBC Solar Cells on the Passivation Quality of Al2O3 and SiO2: Degradation and Regeneration Behavior. Energy Procedia 2017, 124, 365-370. (29)

Kim, K. A.; Krein, P. T. Photovoltaic Hot Spot Analysis for Cells with Various

Reverse-Bias Characteristics Through Electrical and Thermal Simulation, 14th IEEE Workshop on COMPEL, 2013; pp 1-8. (30)

Lu, F.; Guo, S.; Walsh, T. M.; Aberle, A. G., Improved PV Module Performance

under Partial Shading Conditions. Energy Procedia 2013, 33, 248-255.

TOC GRAPHICS

ACS Paragon Plus Environment

18

Page 19 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

a

ACS Applied Energy Materials perovskite top cell

perovskite layer (top)

silicon bottom cell

ACS Paragon Plus Environment

b silicon layer (bottom)

ACS Applied Energy Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Figure 2 119x169mm (300 x 300 DPI)

ACS Paragon Plus Environment

Page 20 of 22

Page 21 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Energy Materials

Figure 3 109x142mm (300 x 300 DPI)

ACS Paragon Plus Environment

ACS Applied Energy Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Figure 4 109x142mm (300 x 300 DPI)

ACS Paragon Plus Environment

Page 22 of 22