ADVERTISEMENT
2 /3 FREE ARTICLES LEFT THIS MONTH Remaining
Chemistry matters. Join us to get the news you need.

If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.

ENJOY UNLIMITED ACCES TO C&EN

Materials

New 2-D perovskite shines white

Ultrathin semiconductor materials showcase glowing potential

by Matt Davenport
March 27, 2017 | APPEARED IN VOLUME 95, ISSUE 13

Perovskites are famous for harvesting light in emerging solar cells, but the inexpensive and easy-to-make semiconductors could also provide a simple path to light-emitting devices.

[+]Enlarge
Credit: J. Am. Chem. Soc.
Changing the organic molecules used in 2-D perovskites influences their physical properties, including their structure and how they photoluminesce. The buckled structure, for example, emits white light.
Credit: J. Am. Chem. Soc.
Changing the organic molecules used in 2-D perovskites influences their physical properties, including their structure and how they photoluminesce. The buckled structure, for example, emits white light.

Commercial white light-emitting diodes are made either by combining different colored LEDs or using LEDs that excite phosphor coatings to produce a white glow. Researchers have previously developed a few two-dimensional perovskite crystals that can emit white light without help, but scientists have yet to use them to build a working LED.

Mercouri G. Kanatzidis, Lingling Mao, and coworkers at Northwestern University have outlined perovskite crystal design considerations that could help change that.

The team developed three new lead-bromide materials using different cationic amine “spacers.” In each, lead-bromide octahedra join to form two-dimensional surfaces. These surfaces stack into layers with the organic molecules sandwiched between.

Two of the team’s perovskite crystals are flat, but the one that uses the smallest cation—2-(dimethylamino)ethylamine or DMEN—takes on a buckled, egg-carton structure. This perovskite also emits light over a broad spectrum of wavelengths, resulting in a white light source with a glow akin to that of a fluorescent bulb, the team reports (J. Amer. Chem. Soc. 2017, DOI: 10.1021/jacs.7b01312).

Edward H. (Ted) Sargent, a photovoltaic materials researcher at the University of Toronto, comments that the work is promising for perovskite LEDs. It provides a “powerful new degree of freedom: engineering perovskites via the length and shape of organic ligand,” he adds.

“This is an inorganic synthetic chemist’s dream,” Kanatzidis says of the versatility of these 2-D perovskites. “The system allows you to make changes and gives you new results every time.”

Advertisement
X

Article:

This article has been sent to the following recipient:

Leave A Comment

*Required to comment