Lead halide perovskite (LHP) semiconductors are promising materials not only for use in solar cells but also for optical devices such as the LEDs in phone, TV and computer screens. While LHPs exhibit bright photoluminescence that would be excellent for crystal-clear displays, they have the disadvantages of being extremely sensitive to light, heat and moisture, as well as posing the risk of toxic lead exposure. LHPs are typically produced in the controlled conditions of a laboratory environment, but a research team at the University of Queensland has proposed a scalable method to create a composite glass with LHP nanocrystals that is both strong and stable while producing bright light and preventing the leaching of lead.
The researchers utilized the method of liquid-phase sintering to combine LHP nanocrystals with metal-organic framework glasses, which binds the nanocrystals to the porous glass, lending them greater stability. The resulting composite was incredibly strong, resistant to cracking, water, heat, organic solvents and other influences, and prevented the leaching of lead from the LHP. The composite also exhibited incredibly clear and bright photoluminescence — about two orders of magnitude greater than pure perovskite — and maintained about 80% photoluminescence after being immersed in water for 10,000 hours. This study was published in the journal Science.
“Not only can we make these nanocrystals more robust but we can tune their opto-electronic properties with fantastic light emission efficiency and highly desirable white light LEDs,” said study co-author Vicky Chen. “This discovery opens up a new generation of nanocrystal-glass composites for energy conversion and catalysis.”
By making a material stronger than typical glass that can resist the elements and provide a bright, clear display, this method could allow for both better devices and more scalability in producing LHP semiconductor materials.