scholarly journals Tailoring solvent coordination for high-speed, room-temperature blading of perovskite photovoltaic films

2019 ◽  
Vol 5 (12) ◽  
pp. eaax7537 ◽  
Author(s):  
Yehao Deng ◽  
Charles H. Van Brackle ◽  
Xuezeng Dai ◽  
Jingjing Zhao ◽  
Bo Chen ◽  
...  

The efficiencies of small-pixel perovskite photovoltaics have increased to above 24%, while most reported fabrication methods cannot be transferred to scalable manufacturing process. Here, we report a method of fast blading large-area perovskite films at an unprecedented speed of 99 mm/s under ambient conditions by tailoring solvent coordination capability. Combing volatile noncoordinating solvents to Pb2+ and low-volatile, coordinating solvents achieves both fast drying and large perovskite grains at room temperature. The reproducible fabrication yields a certified module efficiency of 16.4%, with an aperture area of 63.7 cm2. This method can be applied for various perovskite compositions. The perovskite modules also show a small temperature coefficient of −0.13%/°C and nearly fully recoverable efficiency after 58 cycles of shading, much better than commercial silicon and thin-film solar modules.

2007 ◽  
Vol 121-123 ◽  
pp. 1193-1198 ◽  
Author(s):  
Rolf Steiger ◽  
Robert Beer ◽  
J.F. Fernandez-Sanchez ◽  
U.E. Spichiger-Keller

Large area coatings containing nanoparticulate metal oxides dispersed in polymers are manufactured at high speed (up to 200 m2 /min.) by curtain- or cascade coating on flexible substrates near room temperature. Simultaneously coated multilayers, which may contain different metal oxides, show interesting new properties for industrial applications. Thick (40 $m) coatings with rare-earth doped aluminum oxide nanoparticles have been commercialized for waterfast ink-jet media which are dry to touch after printing, show photo-parity and are very stable towards water, light and environment if appropriate inks are used. Strong capillary forces due to nanoporosity allow instant ink-absorption. Experimental techniques used to develop these materials and results related to imaging parameters are discussed. Thin layers (1-10 $m) of nanoparticulate, nanoporous TiO2 and LiMn2O4, dispersed in non-electroactive polymers such as polyethylene glycols, can be used as electrodes for rechargeable Li-ion batteries with very fast charge-discharge cycles and high power performance. The excellent ion-conducting properties of unsintered, nanoparticulate coatings of these metal oxides were unexpected and allow applications of temperature sensitive substrates and organic addenda. By coating very thin, almost or totally polymer-free layers of highly-porous, monodisperse aluminum-oxides with minimum particle size, display devices with improved optical efficiency were prepared. These layers have a low refractive index thus allowing for higher intensities of light emitted by organic electro-luminescers in OLED’s and PLED’s. This property is useful for mobile devices as phones and PDA’s. A hitherto unknown, photo-catalytic chemical reaction of the classical green emitter tris-(8-hydroxychinolino)-aluminum (Alq3) has been discovered in coatings of such optically efficient devices after exposing them to daylight in air. An efficient blue-emitting species of Alq3 with another stereochemical structure was directly formed within these layers at room temperature by photolysis in ambient atmosphere. Interesting new applications of specially designed, large-area coated and transparent nanostructured matrices on flexible substrates for optical gas sensors are discussed in more detail in this paper.


2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Weiqing Yuan ◽  
Min Li ◽  
Zhongquan Wen ◽  
Yanling Sun ◽  
Desheng Ruan ◽  
...  

Author(s):  
N. David Theodore ◽  
Donald Y.C Lie ◽  
J. H. Song ◽  
Peter Crozier

SiGe is being extensively investigated for use in heterojunction bipolar-transistors (HBT) and high-speed integrated circuits. The material offers adjustable bandgaps, improved carrier mobilities over Si homostructures, and compatibility with Si-based integrated-circuit manufacturing. SiGe HBT performance can be improved by increasing the base-doping or by widening the base link-region by ion implantation. A problem that arises however is that implantation can enhance strain-relaxation of SiGe/Si.Furthermore, once misfit or threading dislocations result, the defects can give rise to recombination-generation in depletion regions of semiconductor devices. It is of relevance therefore to study the damage and anneal behavior of implanted SiGe layers. The present study investigates the microstructural behavior of phosphorus implanted pseudomorphic metastable Si0.88Ge0.12 films on silicon, exposed to various anneals.Metastable pseudomorphic Si0.88Ge0.12 films were grown ~265 nm thick on a silicon wafer by molecular-beam epitaxy. Pieces of this wafer were then implanted at room temperature with 100 keV phosphorus ions to a dose of 1.5×1015 cm-2.


2021 ◽  
Author(s):  
Wenjing Li ◽  
Shun Li ◽  
Lihua Luo ◽  
Yichen Ge ◽  
Jiaqi Xu ◽  
...  

The catalyst-free oxidative cleavage of (Z)-triaryl-substituted alkenes bearing pyridyl motif with ambient air under irradiation of blue LED at room temperature has been developed. The reaction was facile and scalable,...


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
So Yeong Jeong ◽  
Hye Rin Shim ◽  
Yunha Na ◽  
Ki Suk Kang ◽  
Yongmin Jeon ◽  
...  

AbstractWearable electronic devices are being developed because of their wide potential applications and user convenience. Among them, wearable organic light emitting diodes (OLEDs) play an important role in visualizing the data signal processed in wearable electronics to humans. In this study, textile-based OLEDs were fabricated and their practical utility was demonstrated. The textile-based OLEDs exhibited a stable operating lifetime under ambient conditions, enough mechanical durability to endure the deformation by the movement of humans, and washability for maintaining its optoelectronic properties even in water condition such as rain, sweat, or washing. In this study, the main technology used to realize this textile-based OLED was multi-functional near-room-temperature encapsulation. The outstanding impermeability of TiO2 film deposited at near-room-temperature was demonstrated. The internal residual stress in the encapsulation layer was controlled, and the device was capped by highly cross-linked hydrophobic polymer film, providing a highly impermeable, mechanically flexible, and waterproof encapsulation.


2020 ◽  
Vol 6 (10) ◽  
pp. eaau4819 ◽  
Author(s):  
Irnela Bajrovic ◽  
Stephen C. Schafer ◽  
Dwight K. Romanovicz ◽  
Maria A. Croyle

A novel, thin-film platform that preserves live viruses, bacteria, antibodies, and enzymes without refrigeration for extended periods of time is described. Studies with recombinant adenovirus in an optimized formulation that supports recovery of live virus through 16 freeze-thaw cycles revealed that production of an amorphous solid with a glass transition above room temperature and nitrogen-hydrogen bonding between virus and film components are critical determinants of stability. Administration of live influenza virus in the optimized film by the sublingual and buccal routes induced antibody-mediated immune responses as good as or better than those achieved by intramuscular injection. This work introduces the possibility of improving global access to a variety of medicines by offering a technology capable of reducing costs of production, distribution, and supply chain maintenance.


2021 ◽  
Vol 7 (21) ◽  
pp. eabf8049
Author(s):  
Rui Su ◽  
Sanjib Ghosh ◽  
Timothy C. H. Liew ◽  
Qihua Xiong

Strong light-matter interaction enriches topological photonics by dressing light with matter, which provides the possibility to realize active nonlinear topological devices with immunity to defects. Topological exciton polaritons—half-light, half-matter quasiparticles with giant optical nonlinearity—represent a unique platform for active topological photonics. Previous demonstrations of exciton polariton topological insulators demand cryogenic temperatures, and their topological properties are usually fixed. Here, we experimentally demonstrate a room temperature exciton polariton topological insulator in a perovskite zigzag lattice. Polarization serves as a degree of freedom to switch between distinct topological phases, and the topologically nontrivial polariton edge states persist in the presence of onsite energy perturbations, showing strong immunity to disorder. We further demonstrate exciton polariton condensation into the topological edge states under optical pumping. These results provide an ideal platform for realizing active topological polaritonic devices working at ambient conditions, which can find important applications in topological lasers, optical modulation, and switching.


Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 690
Author(s):  
Leonardo Ranasinghe ◽  
Christian Heyn ◽  
Kristian Deneke ◽  
Michael Zocher ◽  
Roman Korneev ◽  
...  

Epitaxially grown quantum dots (QDs) are established as quantum emitters for quantum information technology, but their operation under ambient conditions remains a challenge. Therefore, we study photoluminescence (PL) emission at and close to room temperature from self-assembled strain-free GaAs quantum dots (QDs) in refilled AlGaAs nanoholes on (001)GaAs substrate. Two major obstacles for room temperature operation are observed. The first is a strong radiative background from the GaAs substrate and the second a significant loss of intensity by more than four orders of magnitude between liquid helium and room temperature. We discuss results obtained on three different sample designs and two excitation wavelengths. The PL measurements are performed at room temperature and at T = 200 K, which is obtained using an inexpensive thermoelectric cooler. An optimized sample with an AlGaAs barrier layer thicker than the penetration depth of the exciting green laser light (532 nm) demonstrates clear QD peaks already at room temperature. Samples with thin AlGaAs layers show room temperature emission from the QDs when a blue laser (405 nm) with a reduced optical penetration depth is used for excitation. A model and a fit to the experimental behavior identify dissociation of excitons in the barrier below T = 100 K and thermal escape of excitons from QDs above T = 160 K as the central processes causing PL-intensity loss.


2001 ◽  
Vol 13 (12) ◽  
pp. 1349-1351 ◽  
Author(s):  
M. Gokkavas ◽  
O. Dosunmu ◽  
M.S. Unlu ◽  
G. Ulu ◽  
R.P. Mirin ◽  
...  

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