A new path opens for developing a nanowire transistor device that can control current with light.

Professor Hong-Gyu Park’s work published in Nano Letters

▲ Participants in the study, from the left, Professor Hong-Gyu Park, Research Professor Jungkil Kim, Ha-Reem Kim (Ph.D. program student) 

The research team of Professor Hong-Gyu Park (KU-KIST Graduate School of Converging Science and Technology, Department of Physics) has developed a new fabrication process to create nanowire transistor devices that can control current with light. The results of this study were published in the January 24 issue of the international journal, Nano Letters (IF: 12.080).

- Authors: Hong-Gyu Park (corresponding author, Korea University), Jungkil Kim (co-primary author, Korea University), Ha-Reem Kim (co-primary author, Korea University)

- Title: Photon-Triggered Current Generation in Chemically-Synthesized Silicon Nanowires. Nano Letters 19, 1269-1274 (2019).

The team had already developed for the first time in the world a nanowire transistor device that can control current using only light by inserting porous silicon into single crystal silicon nanowires (Nature Nanotechnology 12, 963-968 (2017)). However, the nanowire fabrication process used in previous studies had a drawback in that it was difficult to control the length, position, and number of pores of the porous silicon. To improve these disadvantages and improve device utilization, the team developed a new technology for developing nanowire transistors with extremely smooth surface bottom-up silicon nanowires. By using electron-beam lithography and a two-step metal catalytic chemical etching method on silicon nanowires dispersed on a substrate, porous silicon can be inserted with a desired length at the desired position on the nanowire.

The team implemented a nanowire transistor device that operates with light using nanowires made with the new fabrication process. As a result of measuring the current-voltage curve by changing the intensity of light, it was confirmed that a very small current of sub-pA flowed when the device was not irradiated with light, but a significant current amplification occurred when the light was irradiated. By expanding this result, the team was successful in implementing a high-resolution one-dimensional optical detection system by inserting nine porous silicon segments on one nanowire.

▲ (Figure) The fabricated single-channel nanowire device and current-voltage curve measured with light emission

It is expected that by using the nanowire fabrication technology developed in this study, it will become easier to develop a highly sensitive high-resolution camera and a new concept computer that can quickly calculate with light.