Tech Forums & Message Boards. Discuss Newest & Greatest Tech Trends. › Tech Forums & Message Boards. Discuss Newest & Greatest Tech Trends. › General Talk › Fundamental Property of Halide Perovskites
MemberSeptember 10, 2021 at 7:59 pm
University of California, Berkeley, scientists have created a blue light-emitting diode (LED) from a trendy new semiconductor material, halide perovskite, overcoming a major barrier to employing these cheap, easy-to-make materials in electronic devices.
In the process, however, the researchers discovered a fundamental property of halide perovskites that may prove a barrier to their widespread use as solar cells and transistors.
Alternatively, this unique property may open up a whole new world for perovskites far beyond that of today’s standard semiconductors.
In a paper appearing today (January 24, 2020) in the journal Science Advances, UC Berkeley chemist Peidong Yang and his colleagues show that the crystal structure of the halide perovskites changes with temperature, humidity and the chemical environment, disrupting their optical and electronic properties. Without close control of the physical and chemical environment, perovskite devices are inherently unstable. This is not a major problem for traditional semiconductors.
“Some people may say this is a limitation. For me, this is a great opportunity,” said Yang, the S. K. and Angela Chan Distinguished Chair in Energy in the College of Chemistry and director of the Kavli Energy NanoSciences Institute. “This is new physics: a new class of semiconductors that can be readily reconfigured, depending on what sort of environment you put them in. They could be a really good sensor, maybe a really good photoconductor, because they will be very sensitive in their response to light and chemicals.”
Current semiconductors made of silicon or gallium nitride are very stable over a range of temperatures, primarily because their crystal structures are held together by strong covalent bonds. Halide perovskite crystals are held together by weaker ionic bonds, like those in a salt crystal. This means they’re easier to make — they can be evaporated out of a simple solution — but also susceptible to humidity, heat and other environmental conditions.