Physicists from Taiwan have designed and fabricated nano-sized light-emitting diodes (LEDs) that emit light spanning the entire visible spectrum. Although the tiny full-color LEDs aren’t intended for commercial lighting applications, they should be useful in high-resolution microscopy and subwavelength photolithography. The researchers, Yu-Jung Lu, et al., from National Tsing-Hua University in Hsinchu, Taiwan, have published their study on the nano-LEDs in a recent issue of Applied Physics Letters.
The new nano-LEDs have a unique structure that consists of 40-nm-thick nanodisks sandwiched between two layers of nanorods, resulting in a nanodisk-in-nanorod geometry. The nanodisks are made of indium gallium nitride (InGaN), a semiconducting material that is widely used in LEDs and solar cells, while the nanorods are made of gallium nitride (GaN). However, InGaN LEDs capable of emitting light of the entire visible spectrum have not been achieved until now.