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16 Dec 10:24

The Role of Charge Selective Contacts in Perovskite Solar Cell Stability

by Bart Roose, Qiong Wang, Antonio Abate
Advanced Energy Materials The Role of Charge Selective Contacts in Perovskite Solar Cell Stability

Perovskite solar cells have experienced a rapid development since the first report in 2012 with the power conversion efficiency approaching the theoretical limit. Device stability is still one of the remaining challenges for commercialisation. In this Review, the authors address the important role the charge selective contacts play in the long‐term stability of perovskite solar cells.


Abstract

Lead halide perovskite solar cells have rapidly achieved high efficiencies comparable to established commercial photovoltaic technologies. The main focus of the field is now shifting toward improving the device lifetime. Many efforts have been made to increase the stability of the perovskite compound and charge‐selective contacts. The electron and hole selective contacts are responsible for the transport of photogenerated charges out of the solar cell and are in intimate contact with the perovskite absorber. Besides the intrinsic stability of the selective contacts themselves, the interfaces at perovskite/selective contact and metal/selective contact play an important role in determining the overall operational lifetime of perovskite solar cells. This review discusses the impact of external factors, i.e., heat, UV‐light, oxygen, and moisture, and measured conditions, i.e., applied bias on the overall stability of perovskite solar cells (PSCs). The authors summarize and analyze the reported strategies, i.e., material engineering of selective contacts and interface engineering via the introduction of interlayers in the aim of enhancing the device stability of PSCs at elevated temperatures, high humidity, and UV irradiation. Finally, an outlook is provided with an emphasis on inorganic contacts that is believed to be the key to achieving highly stable PSCs.

11 Dec 14:41

Addressing Interfacial Issues in Liquid-Based and Solid-State Batteries by Atomic and Molecular Layer Deposition

Publication date: 19 December 2018

Source: Joule, Volume 2, Issue 12

Author(s): Yang Zhao, Kelly Zheng, Xueliang Sun

Context & Scale

The conventional Li-ion batteries (LIBs) with organic liquid electrolyte have reached their bottleneck in energy density. The flammable non-aqueous liquid electrolytes used in LIBs also cause serious safety concerns, especially for the large-scale battery packs in electric vehicles. In this context, development of solid-state batteries (SSBs) by replacing the liquid electrolyte with solid-state electrolytes (SSEs) is a promising solution to overcome the limitations of the conventional LIBs. However, there are three general challenges regarding the interface between SSEs and electrode materials in SSBs, including mismatch, chemical reactions, and space charge effects. These interfacial issues are key drawbacks of the performances of SSBs.

Atomic layer deposition (ALD) and molecular layer deposition (MLD), two advanced gas-phase thin-film deposition techniques, are considered ideal strategies for overcoming the interfacial issues for SSBs. Unique and beneficial characteristics of ALD/MLD include low growth temperatures, atomic-scale and stoichiometric deposition, and excellent uniformity and conformity, which are difficult for other coating techniques. In this Review, we summarize the recent developments of ALD/MLD techniques in the application of Li batteries, with a special focus on the transition from liquid to solid cells. Different sections, including the fabrication of interfacial materials by ALD/MLD, interfacial engineering on SSEs and electrodes, and thin-film/3D SSBs designed by ALD/MLD, are discussed in detail. Moreover, the future directions and perspectives of ALD/MLD in interfacial engineering for SSBs are disclosed.

Summary

Solid-state batteries (SSBs) have attracted increasing attention as one of the most promising next-generation batteries. However, various challenges remain for SSBs toward practical applications. Particularly, the interfacial issues between solid-state electrolyte (SSEs) and electrodes are critical factors affecting the performances of SSBs. Atomic and molecular layer deposition (ALD and MLD) are considered as ideal strategies for overcoming the interfacial issues facing SSBs. In the past years, promising progress has been reported using ALD/MLD to overcome the interfacial drawbacks in SSBs. In this Review, we summarize the recent progress of ALD/MLD techniques in the application of Li batteries, with a special focus on current progress in the shift from liquid to solid cells. Different sections, including the fabrication of interfacial materials, interfacial engineering on SSEs and electrodes, and thin-film/3D SSBs, are discussed in detail. Moreover, the future directions and perspectives of ALD/MLD in interface engineering for SSBs are disclosed.

13 Dec 15:36

Actively Targeted Deep Tissue Imaging and Photothermal-Chemo Therapy of Breast Cancer by Antibody-Functionalized Drug-Loaded X-Ray-Responsive Bismuth Sulfide@Mesoporous Silica Core–Shell Nanoparticles

by Lihua Li, Yao Lu, Chunyan Jiang, Ye Zhu, Xianfeng Yang, Xiaoming Hu, Zefeng Lin, Yu Zhang, Mingying Peng, Hong Xia, Chuanbin Mao

Abstract

A theranostic platform combining synergistic therapy and real-time imaging attracts enormous attention but still faces great challenges, such as tedious modifications and lack of efficient accumulation in tumor. Here, a novel type of theranostic agent, bismuth sulfide@mesoporous silica (Bi2S3@mPS) core-shell nanoparticles (NPs), for targeted image-guided therapy of human epidermal growth factor receptor-2 (HER-2) positive breast cancer is developed. To generate such NPs, polyvinylpyrrolidone decorated rod-like Bi2S3 NPs are chemically encapsulated with a mesoporous silica (mPS) layer and loaded with an anticancer drug, doxorubicin. The resultant NPs are then chemically conjugated with trastuzumab (Tam, a monoclonal antibody targeting HER-2 overexpressed breast cancer cells) to form Tam-Bi2S3@mPS NPs. By in vitro and in vivo studies, it is demonstrated that the Tam-Bi2S3@mPS bear multiple desired features for cancer theranostics, including good biocompatibility and drug loading ability as well as precise and active tumor targeting and accumulation (with a bismuth content in tumor being ≈16 times that of nontargeted group). They can simultaneously serve both as an excellent contrast enhancement probe (due to the presence of strong X-ray-attenuating bismuth element) for computed tomography deep tissue tumor imaging and as a therapeutic agent to destruct tumors and prevent metastasis by synergistic photothermal-chemo therapy.

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A novel theranostic core–shell nanoparticle is developed to achieve targeted imaging and therapy of breast cancer. The nanoparticle is made of a rod-like Bi2S3 core and a porous silica shell functionalized with a tumor-targeting antibody. It can simultaneously attenuate X-ray for targeted tumor imaging by computed tomography and specifically destruct tumor by synergistic photothermal-chemo therapy.

31 Oct 17:06

Synthesis of N = 8 Armchair Graphene Nanoribbons from Four Distinct Polydiacetylenes

by Robert S. Jordan, Yolanda L. Li, Cheng-Wei Lin, Ryan D. McCurdy, Janice B. Lin, Jonathan L. Brosmer, Kristofer L. Marsh, Saeed I. Khan, K. N. Houk, Richard B. Kaner and Yves Rubin

TOC Graphic

Journal of the American Chemical Society
DOI: 10.1021/jacs.7b08800
06 May 18:05

Direct Patterning of Organic Functional Polymers through Conventional Photolithography and Noninvasive Cross-Link Agents

by Marco A. Squillaci, Feng Qiu, Alessandro Aliprandi, Fan Zhang, Xinliang Feng, Paolo Samorì
Thumbnail image of graphical abstract

A new technique for direct patterning of functional organic polymers using commercial photolithography setups with a minimal loss of the materials' performances is reported. This result is achieved through novel cross-link agents made by boron- and fluorine-containing heterocycles that can react between themselves upon UV- and white-light exposure.

15 Jan 00:48

The interplay of thermally activated delayed fluorescence (TADF) and room temperature organic phosphorescence in sterically-constrained donor-acceptor charge-transfer molecules

Chem. Commun., 2016, 52,2612-2615
DOI: 10.1039/C5CC09645F, Communication
Jonathan S. Ward, Roberto S. Nobuyasu, Andrei S. Batsanov, Przemyslaw Data, Andrew P. Monkman, Fernando B. Dias, Martin R. Bryce
Molecular engineering of phenothiazine-dibenzothiophene-S,S-dioxide molecules is reported.
The content of this RSS Feed (c) The Royal Society of Chemistry
15 Jan 00:46

Accelerating chemoselective peptide bond formation using bis(2-selenylethyl)amido peptide selenoester surrogates

Chem. Sci., 2016, 7,2657-2665
DOI: 10.1039/C5SC03459K, Edge Article
Open Access Open Access
Laurent Raibaut, Marine Cargoet, Nathalie Ollivier, Yun Min Chang, Herve Drobecq, Emmanuelle Boll, Remi Desmet, Jean-Christophe M. Monbaliu, Oleg Melnyk
SeEA latent selenoester: go fast by switching to selenium.
The content of this RSS Feed (c) The Royal Society of Chemistry
10 Jan 23:52

A New Molecular Design Based on Thermally Activated Delayed Fluorescence for Highly Efficient Organic Light Emitting Diodes

by Pachaiyappan Rajamalli, Natarajan Senthilkumar, Parthasarathy Gandeepan, Pei-Yun Huang, Min-Jie Huang, Chen-Zheng Ren-Wu, Chi-Yu Yang, Ming-Jui Chiu, Li-Kang Chu, Hao-Wu Lin and Chien-Hong Cheng

TOC Graphic

Journal of the American Chemical Society
DOI: 10.1021/jacs.5b10950
05 Jan 02:50

Electro-Optics of Colloidal Quantum Dot Solids for Thin-Film Solar Cells

by Xiaoliang Zhang, Carl Hägglund, Erik M. J. Johansson

The electro-optics of thin-film stacks within photovoltaic devices plays a critical role for the exciton and charge generation and therefore the photovoltaic performance. The complex refractive indexes of each layer in heterojunction colloidal quantum dot (CQD) solar cells are measured and the optical electric field is simulated using the transfer matrix formalism. The exciton generation rate and the photocurrent density as a function of the quantum dot solid thickness are calculated and the results from the simulations are found to agree well with the experimentally determined results. It can therefore be concluded that a quantum dot solid may be modeled with this approach, which is of general interest for this type of materials. Optimization of the CQD solar cell is performed by using the optical simulations and a maximum solar energy conversion efficiency of 6.5% is reached for a CQD solid thickness of 300 nm.

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The experimental characterization and modeling of the internal optoelectric behavior and exciton generation rate in the quantum dot solids of the heterojunction PbS colloidal quantum dot solar cell is demonstrated. The proposed model shows good agreement with the experimental results, and the fabricated quantum dot solar cell shows a power conversion efficiency of 6.5%.