Large Photothermal Effect in Sub‐40 nm h‐BN Nanostructures Patterned Via High‐Resolution Ion Beam
Abstract
The controlled nanoscale patterning of 2D materials is a promising approach for engineering the optoelectronic, thermal, and mechanical properties of these materials to achieve novel functionalities and devices. Herein, high‐resolution patterning of hexagonal boron nitride (h‐BN) is demonstrated via both helium and neon ion beams and an optimal dosage range for both ions that serve as a baseline for insulating 2D materials is identified. Through this nanofabrication approach, a grating with a 35 nm pitch, individual structure sizes down to 20 nm, and additional nanostructures created by patterning crystal step edges are demonstrated. Raman spectroscopy is used to study the defects induced by the ion beam patterning and is correlated to scanning probe microscopy. Photothermal and scanning near‐field optical microscopy measure the resulting near‐field absorption and scattering of the nanostructures. These measurements reveal a large photothermal expansion of nanostructured h‐BN that is dependent on the height to width aspect ratio of the nanostructures. This effect is attributed to the large anisotropy of the thermal expansion coefficients of h‐BN and the nanostructuring implemented. The photothermal expansion should be present in other van der Waals materials with large anisotropy and can lead to applications such as nanomechanical switches driven by light.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 24, 2018
- Source ID
- 10.1002/smll.201800072
Entities
People
- Antonio Ambrosio
- Chuong Huynh
- David C. Bell
- Dimitri. N. Basov
- Ido E. Kaminer
- Jing Kong
- Josue J Lopez
- Kenji Watanabe
- Marin Soljačić
- Nicholas Rivera
- Pablo Jarillo‐herrero
- Qiong Ma
- Shengxi Huang
- Siyuan Dai
- Soeren Eyhusen
- Takashi Taniguchi
- Xiao Lin
Organizations
- Air Force Office of Scientific Research
- Army Research Office
- China Scholarship Council
- Columbia University
- FP7 Ideas: European Research Council
- Gordon and Betty Moore Foundation
- Harvard University
- Japan Society for the Promotion of Science
- Massachusetts Institute of Technology
- Ministry of Education, Culture, Sports, Science and Technology
- Nanyang Technological University
- National Institute for Materials Science
- National Science Foundation
- Pennsylvania State University
- United States Department of Energy
- University of California, San Diego