Read by QxMD icon Read

Perovskite solar cells

Abdullah Al Mamun, Tanzila Tasnim Ava, Hyeon Jun Jeong, Mun Seok Jeong, Gon Namkoong
We explore a new characterization approach capable of probing the grain interior (GI) and grain boundary (GB) of a CH3NH3PbI3-xClx perovskite thin film. In particular, we have found that the photoluminescence (PL) spectrum observed for a CH3NH3PbI3-xClx perovskite thin film is asymmetric, and can be deconvoluted using a bi-Gaussian function, representing the ordered and disordered phases of the perovskite film. In order to understand the origin of the ordered and disordered phases of the perovskite film, two-dimensional (2D) PL mapping was performed to resolve the PL spectra at the nanoscale level...
March 20, 2017: Physical Chemistry Chemical Physics: PCCP
Valerio Sarritzu, Nicola Sestu, Daniela Marongiu, Xueqing Chang, Sofia Masi, Aurora Rizzo, Silvia Colella, Francesco Quochi, Michele Saba, Andrea Mura, Giovanni Bongiovanni
Metal-halide perovskite solar cells rival the best inorganic solar cells in power conversion efficiency, providing the outlook for efficient, cheap devices. In order for the technology to mature and approach the ideal Shockley-Queissier efficiency, experimental tools are needed to diagnose what processes limit performances, beyond simply measuring electrical characteristics often affected by parasitic effects and difficult to interpret. Here we study the microscopic origin of recombination currents causing photoconversion losses with an all-optical technique, measuring the electron-hole free energy as a function of the exciting light intensity...
March 20, 2017: Scientific Reports
Yongguang Tu, Jihuai Wu, Zhang Lan, Xin He, Jia Dong, Jinbiao Jia, Panfeng Guo, Jianming Lin, Miaoliang Huang, Yunfang Huang
The organic-inorganic lead halide perovskite layer is a crucial factor for the high performance perovskite solar cell (PSC). We introduce CH3NH3Br in the precursor solution to prepare CH3NH3PbI3-xBrx hybrid perovskite, and an uniform perovskite layer with improved crystallinity and apparent grain contour is obtained, resulting in the significant improvement of photovoltaic performance of PSCs. The effects of CH3NH3Br on the perovskite morphology, crystallinity, absorption property, charge carrier dynamics and device characteristics are discussed, and the improvement of open circuit voltage of the device depended on Br doping is confirmed...
March 17, 2017: Scientific Reports
Ujwal Thakur, Uisik Kwon, Md Mehedi Hasan, Wenping Yin, Dasom Kim, Na Young Ha, Soonil Lee, Tae Kyu Ahn, Hui Joon Park
No abstract text is available yet for this article.
March 16, 2017: Scientific Reports
Artiom Magomedov, Nobuya Sakai, Egidijus Kamarauskas, Marius Franckevičius, Gabrielė Jokubauskaitė, Vygintas Jankauskas, Henry J Snaith, Vytautas Getautis
Perovskite solar cells are considered as promising technology for solar energy conversion with the power conversion efficiencies, currently exceeding 20%. In the majority of the record devices Spiro-OMeTAD is used for the positive charge extraction and transport layer. Although, a number of alternative hole transporting materials with different aromatic or heteroaromatic fragments have already been synthesized, a cheap and well performing hole transporting material is still in huge demand. In this work we present two-step synthesis of a novel carbazole-based hole transporting material...
March 16, 2017: Chemistry, An Asian Journal
Yu Hou, Shuang Yang, Xiao Chen, Chunzhong Li, Huijun Zhao, Huagui Yang
Recently, fully covered and smooth perovskite films can be fabricated by optimized coating methods, however, it is still hard to prepare perovskite films with large grain size and high crystallinity. Given the fact that thermal energy can promote crystallization, we combine the application of solvent with high boiling point and high temperature crystallization, which produce high quality perovskite films with micrometer sized grains. We further investigated the temperature dependence of the thermal induced synthetic strategy that the grains become larger as the temperature elevated...
March 16, 2017: Chemistry: a European Journal
Aibin Huang, Yu Yu, Yan Liu, Songwang Yang, Lei Lei, Shanhu Bao, Xun Cao, Ping Jin
Ultrathin Ni doped CoOx (Ni:CoOx) films were demonstrated by direct current (DC) co-sputtering at room temperature and employed as inorganic hole transport materials for inverted perovskite solar cells. P-type Ni2+ doping introduced in this work was designed to adjust the valence band position of CoOx to match the highest occupied molecular orbital of perovskite absorber material (CH3NH3PbI3), which would effectively inhibit recombination of photo-induced electrons and holes. Moreover, the hole extraction capacity would be further enhanced as a result of the appropriate Ni2+ doping, and hence the power conversion efficiency (PCE) of the devices increased from 3...
March 15, 2017: Nanotechnology
Juan L Delgado, Rafael Sandoval-Torrientes, Nazario Martín, Ramón Tena-Zaera, Silvia Collavini, Ivet Kosta, Jorge Pascual, Inés García-Benito
A variety of novel chemically modified fullerenes, showing different electron accepting capabilities, has been synthesized and used to prepare electron transport layer(ETL)-free solar cells based on perovskite:fullerene blends. In particular, isoxazolino[60] fullerenes are proven to be a good candidate for processing blend films with CH3NH3PbI3 and obtaining enhanced power conversion efficiency (PCE) ETL-free perovskite solar cells, improving state-of-the-art PCE (i.e. 14.3%) for this simplified device architecture...
March 15, 2017: ChemSusChem
Deying Luo, Lichen Zhao, Jiang Wu, Qin Hu, Yifei Zhang, Zhaojian Xu, Yi Liu, Tanghao Liu, Ke Chen, Wenqiang Yang, Wei Zhang, Rui Zhu, Qihuang Gong
The highest efficiencies reported for perovskite solar cells so far have been obtained mainly with methylammonium and formamidinium mixed cations. Currently, high-quality mixed-cation perovskite thin films are normally made by use of antisolvent protocols. However, the widely used "antisolvent"-assisted fabrication route suffers from challenges such as poor device reproducibility, toxic and hazardous organic solvent, and incompatibility with scalable fabrication process. Here, a simple dual-source precursor approach is developed to fabricate high-quality and mirror-like mixed-cation perovskite thin films without involving additional antisolvent process...
March 15, 2017: Advanced Materials
R Clayton Shallcross, Yilong Zheng, S Scott Saavedra, Neal R Armstrong
We show for the first time that the frontier orbital energetics (conduction band minimum (CBM) and valence band maximum (VBM)) of device-relevant, methylammonium bromide (MABr)-doped, formamidinium lead trihalide perovskite (FA-PVSK) thin films can be characterized using UV-Vis spectroelectrochemistry, which provides an additional and straightforward experimental technique for determining energy band values relative to more traditional methods based on photoelectron spectroscopy. FA-PVSK films are processed via a two-step deposition process, known to provide high efficiency solar cells, on semi-transparent indium tin oxide (ITO) and titanium dioxide (TiO2) electrodes...
March 14, 2017: Journal of the American Chemical Society
Guannan Yin, Jiaxin Ma, Hong Jiang, Juan Li, Dong Yang, Fei Gao, Jinghui Zeng, Zhike Liu, Shengzhong Frank Liu
The conduction band energy, conductivity, mobility, and electronic trap states of electron transport layer (ETL) are very important to the efficiency and stability of a planar perovskite solar cell (PSC). However, as the most widely used ETL, TiO2 often needs to be prepared under high temperature and has unfavorable electrical properties such as low conductivity and high electronic trap states. Modifications such as elemental doping are effective methods for improving the electrical properties of TiO2 and the performance of PSCs...
March 20, 2017: ACS Applied Materials & Interfaces
Di Huang, Tenghooi Goh, Jaemin Kong, Yifan Zheng, Suling Zhao, Zheng Xu, André D Taylor
Despite being the most commonly used hole transport layer for p-i-n perovskite solar cells, the conventional PEDOT:PSS layer is far from being optimal for the best photovoltaic performance. Herein, we demonstrate highly conductive thin DMSO-doped PEDOT:PSS layers which significantly enhance the light harvesting, charge extraction, and photocurrent production of organo-lead iodide devices. Both imaging and X-ray analysis reveal that the perovskite thin films grown on DMSO-doped PEDOT:PSS exhibit larger grains with increased crystallinity...
March 14, 2017: Nanoscale
Xiaoli Zheng, Haining Chen, Qiang Li, Yinglong Yang, Zhanhua Wei, Yang Bai, Yongcai Qiu, Dan Zhou, Kam Sing Wong, Shihe Yang
Compared with the conventional perovskite solar cells (PSCs) containing hole-transport materials (HTM), carbon materials based HTM-free PSCs (C-PSCs) have often suffered from inferior power conversion efficiencies (PCEs) arising at least partially from the inefficient hole extraction at perovskite/carbon interface. Here, we show that boron (B) doping of multi-walled carbon nanotubes (B-MWNTs) electrodes are superior in enabling enhanced hole extraction and transport by increasing work function, carrier concentration and conductivity of MWNTs...
March 13, 2017: Nano Letters
Elnaz Ghahremanirad, Agustín Bou, Saeed Olyaee, Juan Bisquert
The analysis of perovskite solar cells by impedance spectroscopy has provided a rich variety of behaviors that demand adequate interpretation. Two main features have been reported: First, different impedance spectral arcs vary in combination; second, inductive loops and negative capacitance characteristics appear as an intrinsic property of the current configuration of perovskite solar cells. Here we adopt a previously developed surface polarization model based on the assumption of large electric and ionic charge accumulation at the external contact interface...
March 15, 2017: Journal of Physical Chemistry Letters
Tobias Schnier, Jennifer Emara, Selina Olthof, Klaus Meerholz
Hybrid organic/inorganic halide perovskites have lately been a topic of great interest in the field of solar cell applications, with the potential to achieve device efficiencies exceeding other thin film device technologies. Yet, large variations in device efficiency and basic physical properties are reported. This is due to unintentional variations during film processing, which have not been sufficiently investigated so far. We therefore conducted an extensive study of the morphology and electronic structure of a large number of CH3NH3PbI3 perovskite where we show how the preparation method as well as the mixing ratio of educts methylammonium iodide and lead(II) iodide impact properties like film formation, crystal structure, density of states, energy levels, and ultimately the solar cell performance...
February 27, 2017: Journal of Visualized Experiments: JoVE
Naoki Yarita, Hirokazu Tahara, Toshiyuki Ihara, Tokuhisa Kawawaki, Ryota Sato, Masaki Saruyama, Toshiharu Teranishi, Yoshihiko Kanemitsu
Metal-halide perovskite nanocrystals (NCs) are promising photonic materials for use in solar cells, light-emitting diodes, and lasers. The optoelectronic properties of these devices are determined by the excitons and exciton complexes confined in their NCs. In this study, we determined the relaxation dynamics of charged excitons and biexcitons in CsPbBr3 NCs using femtosecond transient-absorption (TA), time-resolved photoluminescence (PL), and single-dot second-order photon correlation spectroscopy. Decay times of ~40 and ~200 ps were obtained from the TA and PL decay curves for biexcitons and charged excitons, respectively, in NCs with an average size of 7...
March 13, 2017: Journal of Physical Chemistry Letters
Wei-Ting Wang, Sandeep K Das, Yian Tai
Fully ambient-processed and highly efficient methylamine lead iodide (MAPbI3) perovskite films are very desirable for industrial manufacturing of perovskite solar cells (PSCs). To date, most reported highly efficient MAPbI3 PSCs rely on the fabrication of lead iodide (PbI2) films inside the glovebox. Here we report a simple fabrication method using extra dry isopropanol (IPA100) for obtaining uniform and loosely packed PbI2 film, which leads to a uniform and highly crystalline MAPbI3 film under ambient conditions...
March 10, 2017: ACS Applied Materials & Interfaces
Qiang Guo, Yingxue Xu, Bo Xiao, Bing Zhang, Erjun Zhou, Fuzhi Wang, Yiming Bai, Tasawar Hayat, Ahmed Alsaedi, Zhan'ao Tan
For organic-inorganic perovskite solar cells (PerSCs), the electron transport layer (ETL) plays a crucial role in efficient electron extraction and transport for high performance PerSCs. Fullerene and its derivatives are commonly used as ETL for p-i-n structured PerSCs. However, these spherical small molecules are easy to aggregate with high annealing temperature and thus induce morphology stability problems. N-type conjugated polymers are promising candidates to overcome these problems due to the tunable energy levels, controllable aggregation behaviors, and good film formation abilities...
March 15, 2017: ACS Applied Materials & Interfaces
Robertas Tiazkis, Sanghyun Paek, Maryte Daskeviciene, Tadas Malinauskas, Michael Saliba, Jonas Nekrasovas, Vygintas Jankauskas, Shahzada Ahmad, Vytautas Getautis, Mohammad Khaja Nazeeruddin
The molecular structure of the hole transporting material (HTM) play an important role in hole extraction in a perovskite solar cells. It has a significant influence on the molecular planarity, energy level, and charge transport properties. Understanding the relationship between the chemical structure of the HTM's and perovskite solar cells (PSCs) performance is crucial for the continued development of the efficient organic charge transporting materials. Using molecular engineering approach we have constructed a series of the hole transporting materials with strategically placed aliphatic substituents to investigate the relationship between the chemical structure of the HTMs and the photovoltaic performance...
December 2017: Scientific Reports
A Mohammadpour, B D Wiltshire, Y Zhang, S Farsinezhad, A M Askar, R Kisslinger, Y Ren, P Kar, K Shankar
Single crystal rutile titania nanowires grown by solvothermal synthesis are actively being researched for use as electron transporting scaffolds in perovskite solar cells, in low detection limit ultraviolet photodetectors, in photoelectrochemical water-splitting, and in chemiresistive and electrochemical sensing. The electron drift mobility (μ n ) in solution-grown TiO2 nanowires is very low due to a high density of deep traps, and reduces performance in optoelectronic devices. In this study, the effects of molecular passivation of the nanowire surface by octadecylphosphonic acid (ODPA), on carrier transport in TiO2 nanowire ensembles, were investigated using transient space charge limited current measurements...
April 7, 2017: Nanotechnology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"