LOW TEMPERATURE, SOLUTION-PROCESSED PEROVSKITE SOLAR CELLS AND MODULES WITH AN APERTURE AREA EFFICIENCY OF 11%

ABSTRACT

Planar perovskite solar cells and modules were realized by using low temperature solution-process fabrication procedures. The photovoltaic performance was improved by optimizing a SnO2 electron transport layer and its interface with the perovskite layer. We achieved a power conversion efficiency (PCE) of 17.3% on small area cell (0.09 cm2) with negligible hysteresis and a steady-state PCE equal to 17.4%. Furthermore, shelf life tests showed a relative decrease of only 5% in PCE from its initial value after 1000 h of storage in dark conditions in air (RH 20%). Up-scaling of the technology was implemented entirely in air with fabrication of modules with a high aperture ratio of 91%. The modules delivered a maximum PCE of 13.1% obtained on an active area of 13.8 cm2and of 11.9% on an aperture area of 15.2 cm2 representing state of art performance for fully low temperature solution processed planar perovskite solar modules.

Emanuele Calabrò, Fabio Matteocci, Alessandro Lorenzo Palma, Luigi Vesce, Babak Taheri, Laura Carlini, Igor Pis, Silvia Nappini, Janardan Dagar, Chiara Battocchio, Thomas M. Brown

DOI: 10.1016/j.solmat.2018.05.001

https://www.sciencedirect.com/science/article/pii/S0927024818302150

MoS2 Quantum Dot/Graphene Hybrids for Advanced Interface Engineering of a CH3 NH3 PbI3 Perovskite Solar Cell with an Efficiency of over 20%

ABSTRACT

Interface engineering of organic–inorganic halide perovskite solar cells (PSCs) plays a pivotal role in achieving high power conversion efficiency (PCE). In fact, the perovskite photoactive layer needs to work synergistically with the other functional components of the cell, such as charge transporting/active buffer layers and electrodes. In this context, graphene and related two-dimensional materials (GRMs) are promising candidates to tune “on demand” the interface properties of PSCs. In this work, we fully exploit the potential of GRMs by controlling the optoelectronic properties of molybdenum disulfide (MoS2) and reduced graphene oxide (RGO) hybrids both as hole transport layer (HTL) and active buffer layer (ABL) in mesoscopic methylammonium lead iodide (CH3NH3PbI3) perovskite (MAPbI3)-based PSCs. We show that zero-dimensional MoS2 quantum dots (MoS2 QDs), derived by liquid phase exfoliated MoS2flakes, provide both hole-extraction and electron-blocking properties. In fact, on one hand, intrinsic n-type doping-induced intraband gap states effectively extract the holes through an electron injection mechanism. On the other hand, quantum confinement effects increase the optical band gap of MoS2 (from 1.4 eV for the flakes to >3.2 eV for QDs), raising the minimum energy of its conduction band (from −4.3 eV for the flakes to −2.2 eV for QDs) above the one of the conduction band of MAPbI3 (between −3.7 and −4 eV) and hindering electron collection. The van der Waals hybridization of MoS2 QDs with functionalized reduced graphene oxide (f-RGO), obtained by chemical silanization-induced linkage between RGO and (3-mercaptopropyl)trimethoxysilane, is effective to homogenize the deposition of HTLs or ABLs onto the perovskite film, since the two-dimensional nature of RGO effectively plugs the pinholes of the MoS2 QD films. Our “graphene interface engineering” (GIE) strategy based on van der Waals MoS2 QD/graphene hybrids enables MAPbI3-based PSCs to achieve a PCE up to 20.12% (average PCE of 18.8%). The possibility to combine quantum and chemical effects into GIE, coupled with the recent success of graphene and GRMs as interfacial layer, represents a promising approach for the development of next-generation PSCs.

Leyla Najafi, Babak Taheri, Beatriz Martín-García, Sebastiano Bellani, Diego Di Girolamo, Antonio Agresti, Reinier Oropesa-Nuñez, Sara Pescetelli, Luigi Vesce, Emanuele Calabrò, Mirko Prato, Antonio E. Del Rio Castillo, Aldo Di Carlo, Francesco Bonaccorso

DOI: 10.1021/acsnano.8b05514

ACS Publications
Publication Date (Web): September 21, 2018

https://pubs.acs.org/doi/10.1021/acsnano.8b05514

Sustainable Electronics Based on Crop Plant Extracts and Graphene: a “Bioadvantaged” Approach

ABSTRACT

In today's fast‐paced and well‐connected world, consumer electronics are evolving rapidly. As a result, the amount of discarded electronic devices is becoming a major health and environmental concern. The rapid expansion of flexible electronics has the potential to transform consumer electronic devices from rigid phones and tablets to robust wearable devices. This means increased use of plastics in consumer electronics and the potential to generate more persistent plastic waste for the environment. Hence, today, the need for flexible biodegradable electronics is at the forefront of minimizing the mounting pile of global electronic waste. A “bioadvantaged” approach to develop a biodegradable, flexible, and application‐adaptable electronic components based on crop components and graphene is reported. More specifically, by combining zein, a corn‐derived protein, and aleuritic acid, a major monomer of tomato cuticles and sheellac, along with graphene, biocomposite conductors having low electrical resistance (≈10 Ω sq−1) with exceptional mechanical and fatigue resilience are fabricated. Further, a number of high‐performance electronic applications, such as THz electromagnetic shielding, flexible GHz antenna construction, and flexible solar cell electrode, are demonstrated. Excellent performance results are measured from each application comparable to conventional nondegrading counterparts, thus paving the way for the concept of “plant‐e‐tronics” towards sustainability.

Susana Guzman‐Puyol, Luca Ceseracciu, Luca La Notte, Andrea Reale, Jun Ren, Yijie Zhang, Lei Liu, Mario Miscuglio, Patrizia Savi, Simonluca Piazza, Marti Duocastella, Giovanni Perotto, Athanassia Athanassiou, Ilker S. Bayer

DOI: 10.1002/adsu.201800069

05 August 2018
Advanced Sustainable Systems

https://onlinelibrary.wiley.com/doi/full/10.1002/adsu.201800069

Graphene-Engineered Automated Sprayed Mesoscopic Structure for Perovskite Device Scaling-Up

ABSTRACT

One of the most thrilling developments in the photovoltaic field over recent years has been the use of organic–inorganic lead halide perovskite, such as CH3NH3PbI3 (MAPbI3), as a promising new material for low-cost and highly efficient solar cells. Despite the impressive power conversion efficiency (PCE) exceeding 22% demonstrated on lab-scale devices, large-area material deposition procedures and automatized device fabrication protocols are still challenging to achieve high-throughput serial manufacturing of modules and panels. In this work, we demonstrate that spray coating is an effective technique for the production of mesoscopic small- and large-area perovskite solar cells (PSCs). In particular, we report a sprayed graphene-doped mesoporous TiO2 (mTiO2) scaffold for mesoscopic PSCs. By successfully combining the spray coating technique with the insertion of graphene additive into the sprayed mTiO2 scaffold, a uniform film deposition and a significant enhancement of the electron transport/injection at the mTiO2/perovskite electrode is achieved. The use of graphene flakes on the sprayed scaffold boosts the PCE of small-area cells up to 17.5% that corresponds to an increase of more than 15% compared to standard cells. For large-area (1.1 cm2) cells, a PCE up to 14.96% is achieved. Moreover, graphene-doped mTiO2 layer enhances the stability of the PSCs compared to standard devices. The feasibility of PSC fabrication by spray coating deposition of the mesoporous film on large-area 21  ×  24 cm2 provides a viable and low-cost route to scale up the manufacturing of low-cost, stable and high-efficiency PSCs.

Babak Taheri, Narges Yaghoobi Nia, Antonio Agresti, Sara Pescetelli, Claudio Ciceroni, Antonio Esaù Del Rio Castillo, Lucio Cinà, Sebastiano Bellani, Francesco Bonaccorso, Aldo Di Carlo

DOI: 10.1088/2053-1583/aad983

25 September 2018
2D Materials

http://iopscience.iop.org/article/10.1088/2053-1583/aad983/meta

A NOVEL CLASS OF DYE-SENSITIZED SOLAR MODULES. GLASS-PLASTIC STRUCTURE FOR MECHANICALLY STABLE DEVICES

ABSTRACT

Owing to its peculiar properties such as transparency, weak angle dependence and improved power conversion efficiency (PCE) at diffused light, DSSCs (Dye Sensitized Solar Cells) are well suited for Building Integrated PhotoVoltaic (BIPV). For large area DSSC devices and modules, one of the main causes of sealing failure is the deformation of the glass substrates due to the sintering process of TiO 2 which occurs significantly at temperatures around 500 °C. The novel class of realized DSSMs (Dye Sensitized Solar Modules) consists in a “Glass/Plastic hybrid” structure with a photo-electrode developed on glass-FTO and a counter-electrode developed on PET-ITO. By adopting this unique solution, it is possible to anneal the photo-electrode at temperatures above 500°C for an optimal TiO 2 sintering and to improve the sturdiness of the devices adapting the flexible counter-electrode on the rigid photo-electrode. Developing the counter-electrode on PET-ITO we halved the thickness and weight of the devices, strengthens the commitment of DSSC technology in BIPV sector where the weights and the volumes occupied by components play a fundamental role in design, fabrication and costs. devices, as alternatives to batteries for small electronic goods market.

Paolo Mariani, Luigi Vesce, Aldo Di Carlo

DOI: 10.1109/RTSI.2018.8548439

2018 IEEE 4th International Forum on Research and Technology for Society and Industry (RTSI) Proceedings

https://ieeexplore.ieee.org/abstract/document/8548439

THERMALLY INDUCED FULLERENE DOMAIN COARSENING PROCESS IN ORGANIC SOLAR CELLS

ABSTRACT

The recent advancements in power conversion efficiency for organic solar cells is still complained by their reliability and stability remaining the main bottlenecks for organic photovoltaics large scale production and commercialization. In this paper, we aim to provide further insights understanding in degradation processes affecting stability in small molecule flat heterojunction (Glass/ITO/MoO₃/ZnPc/C₆₀/BCP/Ag) solar cells through a systematic aging study coupled with optoelectrical characterizations. In particular, the burn-in phenomenon affecting short-circuit current in thermal-stressed samples has been clearly correlated with the C₆₀ domain coarsening process and eventually to the decreased exciton lifetime.

Antonio Agresti, Sara Pescetelli, Yan Busby, Tom Aernouts

DOI: 10.1109/TED.2018.2880760

IEEE Transactions on Electron Devices PP(99):1-11 · November 2018

https://www.researchgate.net/publication/329199419_Thermally_Induced_Fullerene_Domain_Coarsening_Process_in_Organic_Solar_Cells