Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Meniscus-assisted technique produces high efficiency perovskite PV films

This is an optical micrograph of perovskite crystal grains crafted by meniscus-assisted solution printing.
CREDIT
Image courtesy of Ming He, Georgia Tech
This is an optical micrograph of perovskite crystal grains crafted by meniscus-assisted solution printing. CREDIT Image courtesy of Ming He, Georgia Tech

Abstract:
A new low-temperature solution printing technique allows fabrication of high-efficiency perovskite solar cells with large crystals intended to minimize current-robbing grain boundaries. The meniscus-assisted solution printing (MASP) technique boosts power conversion efficiencies to nearly 20 percent by controlling crystal size and orientation.

Meniscus-assisted technique produces high efficiency perovskite PV films

Atlanta, GA | Posted on July 7th, 2017

The process, which uses parallel plates to create a meniscus of ink containing the metal halide perovskite precursors, could be scaled up to rapidly generate large areas of dense crystalline film on a variety of substrates, including flexible polymers. Operating parameters for the fabrication process were chosen by using a detailed kinetics study of perovskite crystals observed throughout their formation and growth cycle.

"We used a meniscus-assisted solution printing technique at low temperature to craft high quality perovskite films with much improved optoelectronic performance," said Zhiqun Lin, a professor in the School of Materials Science and Engineering at the Georgia Institute of Technology. "We began by developing a detailed understanding of crystal growth kinetics that allowed us to know how the preparative parameters should be tuned to optimize fabrication of the films."

The new technique is reported July 7 in the journal Nature Communications. The research has been supported by the Air Force Office of Scientific Research (AFOSR) and the National Science Foundation (NSF).

Perovskites offer an attractive alternative to traditional materials for capturing electricity from light, but existing fabrication techniques typically produce small crystalline grains whose boundaries can trap the electrons produced when photons strike the materials. Existing production techniques for preparing large-grained perovskite films typically require higher temperatures, which is not favorable for polymer materials used as substrates - which could help lower the fabrication costs and enable flexible perovskite solar cells.

So Lin, Research Scientist Ming He and colleagues decided to try a new approach that relies on capillary action to draw perovskite ink into a meniscus formed between two nearly parallel plates approximately 300 microns apart. The bottom plate moves continuously, allowing solvent to evaporate at the meniscus edge to form crystalline perovskite. As the crystals form, fresh ink is drawn into the meniscus using the same physical process that forms a coffee ring on an absorbent surface such as paper.

"Because solvent evaporation triggers the transport of precursors from the inside to the outside, perovskite precursors accumulate at the edge of the meniscus and form a saturated phase," Lin explained. "This saturated phase leads to the nucleation and growth of crystals. Over a large area, we see a flat and uniform film having high crystallinity and dense growth of large crystals."

To establish the optimal rate for moving the plates, the distance between plates and the temperature applied to the lower plate, the researchers studied the growth of perovskite crystals during MASP. Using movies taken through an optical microscope to monitor the grains, they discovered that the crystals first grow at a quadratic rate, but slow to a linear rate when they began to impinge on their neighbors.

"When the crystals run into their neighbors, that affects their growth," noted He. "We found that all of the grains we studied followed similar growth dynamics and grew into a continuous film on the substrate."

The MASP process generates relatively large crystals - 20 to 80 microns in diameter - that cover the substrate surface. Having a dense structure with fewer crystals minimizes the gaps that can interrupt the current flow, and reduces the number of boundaries that can trap electrons and holes and allow them to recombine.

Using films produced with the MASP process, the researchers have built solar cells that have power conversion efficiencies averaging 18 percent - with some as high as 20 percent. The cells have been tested with more than 100 hours of operation without encapsulation. "The stability of our MASP film is improved because of the high quality of the crystals," Lin said.

Doctor-blading is one of the conventional perovskite fabrication techniques in which higher temperatures are used to evaporate the solvent. Lin and his colleagues heated their substrate to only about 60 degrees Celsius, which would be potentially compatible with polymer substrate materials.

So far, the researchers have produced centimeter-scale samples, but they believe the process could be scaled up and applied to flexible substrates, potentially facilitating roll-to-roll continuous processing of the perovskite materials. That could help lower the cost of producing solar cells and other optoelectronic devices.

"The meniscus-assisted solution printing technique would have advantages for flexible solar cells and other applications requiring a low-temperature continuous fabrication process," Lin added. "We expect the process could be scaled up to produce high throughput, large-scale perovskite films."

Among the next steps are fabricating the films on polymer substrates, and evaluating other unique properties (e.g., thermal and piezotronic) of the material.

###

This research was supported by the Air Force Office of Scientific Research (MURI FA9550-14-1-0037; FA9550-16-1-0187) and National Science Foundation (CMMI-1562075). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the sponsoring agencies.

####

For more information, please click here

Contacts:
John Toon

404-894-6986

Copyright © Georgia Institute of Technology

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

CITATION: Ming He, Bo Li, Xun Cui, Beibei Jiang, Yanjie He, Yihuang Chen, Daniel O'Neil, Paul Szymanski, Mostafa A. EI-Sayed, Jinsong Huang and Zhiqun Lin, "Meniscus-assisted solution printing of large-grained perovskite films for high-efficiency solar cells," (Nature Communications, 2017).:

Related News Press

News and information

The first light atomic nucleus with a second face July 20th, 2017

Semiliquid chains pulled out of a sea of microparticles July 20th, 2017

Tokyo Institute of Technology research: Antiaromatic molecule displays record electrical conductance July 19th, 2017

Harnessing light to drive chemical reactions July 19th, 2017

Perovskites

Development of low-dimensional nanomaterials could revolutionize future technologies June 15th, 2017

Ultra-stable perovskite solar cell remains stable for more than a year June 1st, 2017

Next generation perovskite solar cells with new world-record performance April 3rd, 2017

New nanofiber marks important step in next generation battery development March 14th, 2017

Govt.-Legislation/Regulation/Funding/Policy

The first light atomic nucleus with a second face July 20th, 2017

Semiliquid chains pulled out of a sea of microparticles July 20th, 2017

Here's a tip: Indented cement shows unique properties: Rice University models reveal nanoindentation can benefit crystals in concrete July 20th, 2017

Harnessing light to drive chemical reactions July 19th, 2017

Possible Futures

Semiliquid chains pulled out of a sea of microparticles July 20th, 2017

Here's a tip: Indented cement shows unique properties: Rice University models reveal nanoindentation can benefit crystals in concrete July 20th, 2017

Tokyo Institute of Technology research: Antiaromatic molecule displays record electrical conductance July 19th, 2017

Harnessing light to drive chemical reactions July 19th, 2017

Discoveries

The first light atomic nucleus with a second face July 20th, 2017

Semiliquid chains pulled out of a sea of microparticles July 20th, 2017

Here's a tip: Indented cement shows unique properties: Rice University models reveal nanoindentation can benefit crystals in concrete July 20th, 2017

Harnessing light to drive chemical reactions July 19th, 2017

Materials/Metamaterials

Carbon displays quantum effects July 13th, 2017

ANU invention may help to protect astronauts from radiation in space July 3rd, 2017

Brookhaven Scientists Study Role of 'Electrolyte Gating' in Functional Oxide Materials July 3rd, 2017

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Announcements

The first light atomic nucleus with a second face July 20th, 2017

Semiliquid chains pulled out of a sea of microparticles July 20th, 2017

Here's a tip: Indented cement shows unique properties: Rice University models reveal nanoindentation can benefit crystals in concrete July 20th, 2017

Harnessing light to drive chemical reactions July 19th, 2017

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

The first light atomic nucleus with a second face July 20th, 2017

Semiliquid chains pulled out of a sea of microparticles July 20th, 2017

Here's a tip: Indented cement shows unique properties: Rice University models reveal nanoindentation can benefit crystals in concrete July 20th, 2017

Tokyo Institute of Technology research: Antiaromatic molecule displays record electrical conductance July 19th, 2017

Military

Nanoparticles could spur better LEDs, invisibility cloaks July 19th, 2017

'Upconverted' light has a bright future: Rice University professor developing plasmon-powered devices for medicine, security, solar cells July 17th, 2017

Nature-inspired material uses liquid reinforcement: Rice U. nanoengineers create liquid-solid composites using clues from nature July 11th, 2017

Research accelerates quest for quicker, longer-lasting electronics: UC Riverside-led research makes topological insulators magnetic well above room temperatures June 25th, 2017

Printing/Lithography/Inkjet/Inks/Bio-printing

Carbodeon demonstrates NanoDiamond nickel coatings with enhanced tribological properties June 7th, 2017

Liquid metal nano printing set to revolutionize electronics: Creating integrated circuits just atoms thick February 18th, 2017

New stem cell technique shows promise for bone repair January 25th, 2017

NUS researchers achieve major breakthrough in flexible electronics: New classes of printable electrically conducting polymer materials make better electrodes for plastic electronics and advanced semiconductor devices January 14th, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project