High-Yield Gas-Phase Laser Photolysis Synthesis of Germanium Nanocrystals for High-Performance Photodetectors and Lithium Ion Batteries

• Published in: Journal of physical chemistry. C 2012-12, Vol.116 (50), p.26190-26196
• Main Authors: Kim, Chang Hyun, Im, Hyung Soon, Cho, Yong Jae, Jung, Chan Su, Jang, Dong Myung, Myung, Yoon, Kim, Han Sung, Back, Seung Hyuk, Lim, Young Rok, Lee, Chi-Woo, Park, Jeunghee, Song, Min Seob, Cho, Won-Il
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electronics; Exact sciences and technology; Laser-assisted deposition; Materials science; Methods of nanofabrication; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Optoelectronic devices; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp308852g

We developed a new high-yield synthesis method of free-standing germanium nanocrystals (Ge NCs) by means of the gas-phase photolysis of tetramethyl germanium in a closed reactor using a Nd:YAG pulsed laser. The as-grown Ge NCs are sheathed with thin (1–2 nm) carbon layers, and size control (5–100 nm) can be simply achieved using a quenching gas. The hybrid nanostructures of the quantum-confined Ge NCs and reduced graphene oxide (RGO) become transparent flexible photodetectors that respond sensitively over the UV–visible–NIR wavelength range. Both Ge NCs and Ge–RGO hybrids exhibit excellent cycling performance and high capacity of the lithium ion battery (800 and 1100 mA h/g after 50 cycles, respectively) as promising anode materials for the development of high-performance lithium batteries.