Gao, Sen Hong, Sanghyun Park, Soohyung Jung, Hyun Young Liang, Wentao Lee, Yonghee Ahn, Chi Won Byun, Ji Young Seo, Juyeon Hahm, Myung Gwan Kim, Hyehee Kim, Kiwoong Yi, Yeonjin Wang, Hailong Upmanyu, Moneesh Lee, Sung-Goo Homma, Yoshikazu Terrones, Humberto Jung, Yung Joon 2024-01-19T12:00:32Z 2024-01-19T12:00:32Z 2022-07-08 2022-06 2041-1723 https://pubs.kist.re.kr/handle/201004/115111 The need for miniaturized and high-performance devices has attracted enormous attention to the development of quantum silicon nanowires. However, the preparation of abundant quantities of silicon nanowires with the effective quantum-confined dimension remains challenging. Here, we prepare highly dense and vertically aligned sub-5 nm silicon nanowires with length/diameter aspect ratios greater than 10,000 by developing a catalyst-free chemical vapor etching process. We observe an unusual lattice reduction of up to 20% within ultra-narrow silicon nanowires and good oxidation stability in air compared to conventional silicon. Moreover, the material exhibits a direct optical bandgap of 4.16 eV and quasi-particle bandgap of 4.75 eV with the large exciton binding energy of 0.59 eV, indicating the significant phonon and electronic confinement. The results may provide an opportunity to investigate the chemistry and physics of highly confined silicon quantum nanostructures and may explore their potential uses in nanoelectronics, optoelectronics, and energy systems. The preparation of quantum silicon nanowires, materials with potential application in high-performance nanodevices, is challenging. Here, the authors synthesize vertically aligned sub-5 nm silicon nanowires via a vapor phase silicon etching process; the resulting material features unusual lattice reduction and significant phonon and electronic confinement effects. English Nature Publishing Group Catalyst-free synthesis of sub-5 nm silicon nanowire arrays with massive lattice contraction and wide bandgap Article 10.1038/s41467-022-31174-x 1 Nature Communications, v.13, no.1 Nature Communications 13 1 Y scie scopus 000813768100008 Multidisciplinary Sciences Science & Technology - Other Topics Article SELF-LIMITING OXIDATION ELASTIC PROPERTIES OXIDE-GROWTH SI NANOWIRES LEDGE-FLOW DIAMETER SURFACE SCATTERING FABRICATION ABSORPTION