MECHANICALLY STACKED, TWO-TERMINAL GRAPHENE-BASED PEROVSKITE/SILICON TANDEM SOLAR CELL WITH EFFICIENCY OVER 26%

SUMMARY

Perovskite/silicon tandem solar cells represent an attractive pathway to upgrade the market-leading crystalline silicon technology beyond its theoretical limit. Two-terminal architectures result in reduced plant costs compared to four-terminal ones. However, it is challenging to monolithically process perovskite solar cells directly onto the micrometer-sized texturing on the front surface of record-high efficiency amorphous/crystalline silicon heterojunction cells, which limits both high-temperature and solution processing of the top cells. To tackle these hurdles, we present a mechanically stacked two-terminal perovskite/silicon tandem solar cell, with the sub-cells independently fabricated, optimized, and subsequently coupled by contacting the back electrode of the mesoscopic perovskite top cell with the texturized and metalized front contact of the silicon bottom cell. By minimizing optical losses, as achieved by engineering the hole selective layer/rear contact structure, and using a graphene-doped mesoporous electron selective layer for the perovskite top cell, the champion tandem device demonstrates a 26.3% efficiency (25.9% stabilized) over an active area of 1.43 cm2.

Authors:

Enrico Lamanna, Fabio Matteocci, Emanuele Calabrò, Luca Serenelli, Enrico Salza, Luca Martini, Francesca Menchini, Massimo Izzi, Antonio Agresti, Sara Pescetelli, Sebastiano Bellani, Antonio Esaú Del Río Castillo, Francesco Bonaccorso, Mario Tucci, Aldo Di Carlo

https://doi.org/10.1016/j.joule.2020.01.015

International Magazine "Joule", 17 February 2020

https://www.sciencedirect.com/science/article/abs/pii/S2542435120300453?via%3Dihub

THE MOLECULAR WEIGHT DEPENDENCE OF THERMOELECTRIC PROPERTIES OF POLY (3-HEXYLTHIOPHENE)

ABSTRACT

Organic materials have been found to be promising candidates for low-temperature thermoelectric applications. In particular, poly (3-hexylthiophene) (P3HT) has been attracting great interest due to its desirable intrinsic properties, such as excellent solution processability, chemical and thermal stability, and high field-effect mobility. However, its poor electrical conductivity has limited its application as a thermoelectric material. It is therefore important to improve the electrical conductivity of P3HT layers. In this work, we studied how molecular weight (MW) influences the thermoelectric properties of P3HT films. The films were doped with lithium bis(trifluoromethane sulfonyl) imide salt (LiTFSI) and 4-tert butylpyridine (TBP). Various P3HT layers with different MWs ranging from 21 to 94 kDa were investigated. UV–Vis spectroscopy and atomic force microscopy (AFM) analysis were performed to investigate the morphology and structure features of thin films with different MWs. The electrical conductivity initially increased when the MW increased and then decreased at the highest MW, whereas the Seebeck coefficient had a trend of reducing as the MW grew. The maximum thermoelectric power factor (1.87 μW/mK2) was obtained for MW of 77 kDa at 333 K. At this temperature, the electrical conductivity and Seebeck coefficient of this MW were 65.5 S/m and 169 μV/K, respectively.

Authors:

Saeed Mardi, Marialilia Pea, Andrea Notargiacomo, Narges Yaghoobi Nia, Aldo Di Carlo, Andrea Reale

https://doi.org/10.3390/ma13061404

MDPI Journals - Materials, 13(6), 1404, 19/03/2020

https://www.mdpi.com/1996-1944/13/6/1404

DOPING STRATEGY FOR EFFICIENT AND STABLE TRIPLE CATION HYBRID PEROVSKITE SOLAR CELLS AND MODULE BASED ON POLY(3-HEXYLTHIOPHENE) HOLE TRANSPORT LAYER

ABSTRACT

As the hole transport layer (HTL) for perovskite solar cells (PSCs), poly(3‐hexylthiophene) (P3HT) has been attracting great interest due to its low‐cost, thermal stability, oxygen impermeability, and strong hydrophobicity. In this work, a new doping strategy is developed for P3HT as the HTL in triple‐cation/double‐halide ((FA1−x−yMAxCsy)Pb(I1−xBrx)3) mesoscopic PSCs. Photovoltaic performance and stability of solar cells show remarkable enhancement using a composition of three dopants Li‐TFSI, TBP, and Co(III)‐TFSI reaching power conversion efficiencies of 19.25% on 0.1 cm2 active area, 16.29% on 1 cm2 active area, and 13.3% on a 43 cm2 active area module without using any additional absorber layer or any interlayer at the PSK/P3HT interface. The results illustrate the positive effect of a cobalt dopant on the band structure of perovskite/P3HT interfaces leading to improved hole extraction and a decrease of trap‐assisted recombination. Non‐encapsulated large area devices show promising air stability through keeping more than 80% of initial efficiency after 1500 h in atmospheric conditions (relative humidity ≈ 60%, r.t.), whereas encapsulated devices show more than >500 h at 85 °C thermal stability (>80%) and 100 h stability against continuous light soaking (>90%). The boosted efficiency and the improved stability make P3HT a good candidate for low‐cost large‐scale PSCs.

Authors:

Narges Yaghoobi Nia, Enrico Lamanna, Mahmoud Zendehdel, Alessandro L. Palma, Francesca Zurlo, Luigi Angelo Castriotta, Aldo Di Carlo

https://doi.org/10.1002/smll.201904399

"Nano-Micro Small", Volume15, Issue 49, December 6, 2019, 1904399

(first publication: 08 October 2019)

https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.201904399https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.201904399

SOLUTION-BASED HETEROEPITAXIAL GROWTH OF STABLE MIXED CATION/ANION HYBRID PEROVSKITE THIN FILM UNDER AMBIENT CONDITION VIA A SCALABLE CRYSTAL ENGINEERING APPROACH

ABSTRACT

The performance of perovskite solar cells is under direct control of the perovskite film quality and controlling the crystalinity and orientation of solution-processed perovskite film is a fundamental challenge. In this study, we present a scalable fabrication process for heteroepitaxial growth of mixed-cation hybrid perovskites (FA1-x-yMAxCsy)Pb(I1-xBrx)3 in ambient atmospheric condition by using a Crystal Engineering (CE) approach. Smooth and mesoporous thin film of pure crystalline intermediate phase of PbX2.2DMSO is formed by deposition of supersaturated lead/cesium halides solution. Kinetically fast perovskite nucleation is achieved by rapid intercalation of formamidinium iodide (FAI) and methylammonium bromide (MABr) into the intermediate layer trough solvent assisted SN1 ligand exchange. Finally, heteroepitaxially perovskite growth is accomplished via Volmer−Weber crystal growth mechanism. All the layers are deposited under atmospheric condition (relative humidity (RH) 50–75%) with high reproducibility for various device and module dimensions. In particular, perovskite solar modules (Pmax ~550 mW) are successfully fabricated by blade coating under atmospheric condition. The CE approach remarkably improves the device performance by reaching a power conversion efficiency of 18.4% for small area (0.1 cm2), 16.5% on larger area (1 cm2) devices, and 12.7% and 11.6% for blade-coated modules with an active area of 17 and 50 cm2, respectively. Non-encapsulated triple cation solar cells and modules show promising stability under atmospheric shelf life and light soaking conditions.

Authors:

Narges Yaghoobi Nia, Fabrizio Giordano, Mahmoud Zendehdel, Lucio Cinà, Alessandro Lorenzo Palma, Pier Gianni Medaglia, Shaik Mohammed Zakeeruddin, Michael Grätzel, Aldo Di Carlo 

https://doi.org/10.1016/j.nanoen.2019.104441

"Nano Energy", Volume 69, March 2020, 104441

https://www.sciencedirect.com/science/article/abs/pii/S2211285519311589#!

LOW TEMPERATURE PROCESS OF HOMOGENEOUS AND PIN-HOLE FREE PEROVSKITE LAYERS FOR FULLY COATED PHOTOVOLTAIC DEVICES UP TO 256 CM2 AREA AT AMBIENT CONDITION

ABSTRACT

The versatility of printing/coating technologies together with the development of new hybrid and organic materials permit to revolutionize the photovoltaic (PV) research and manufacture. Among the new PV concept, perovskite solar cell technology has ascended top efficiencies in few years. The low-cost perspective of this III-GEN PV is however achievable only at industrial production levels. To this end, we developed a simple yet scalable process for production of monolithic Perovskite solar modules (PSMs). Here we use the doctor blade coating technique assisted by a hot air flow. The basic setup is easy to build and permits to obtain a homogeneous and repeatable deposition of the layers forming the PSM. By applying this fabrication method at ambient condition, we fabricated a low temperature module up to 40 cm2 with a conversion efficiency above 11% and a perovskite layer up to 256 cm2, both based on a pinhole free one-step (without any anti-solvent technique) method, demonstrating the scaling up capability of the optimised process.

Authors: 

Luigi Vesce, Maurizio Stefanelli, Aldo Di Carlo

https://doi.org/10.1109/ISAECT47714.2019.9069678

2019 International Symposium on Advanced Electrical and Communication Technologies (ISAECT)

THIAZOLO[5,4-D]THIAZOLE-BASED ORGANIC SENSITIZERS WITH IMPROVED SPECTRAL PROPERTIES FOR APPLICATION IN GREENHOUSE-INTEGRATED DYE-SENSITIZED SOLAR CELLS

ABSTRACT

Organic photosensitizers especially designed for producing semitransparent dye-sensitized solar cells (DSSCs) for greenhouse integration were prepared by introduction of different heterocyclic moieties into the thiazolo[5,4-d]thiazolemolecular scaffold. The aim was that of improving their light absorption capability in the green part of the visible spectrum while maintaining a good transparency in the blue and red regions, where the photosynthetic response is maximized. A short and efficient synthetic approach, featuring two consecutive C-H activation reactions in a one-pot procedure as key steps, was used. Based on their spectroscopic and electrochemical characterization, two of dyes prepared appeared especially suitable for greenhouse-integrated photovoltaics. The corresponding semitransparent DSSCs yielded 5.6-6.1% power conversion efficiencies, which were largely superior to those provided by other organic dyes previously proposed for the same application.

Authors:

Alessio Dessì, Massimo Calamante, Adalgisa Sinicropi, Maria Laura Parisi, Luigi Vesce, Paolo Mariani, Babak Taheri, Manuela Ciocca, Aldo Di Carlo, Lorenzo Zani, Alessandro Mordini, Gianna Reginato

https://doi.org/10.1039/D0SE00124D

Sustainable Energy & Fuels 2020