Related Experiment Video
Updated: Feb 5, 2026

Preparation of Carbon Nanosheets at Room Temperature
Published on: March 8, 2016
Room-temperature excitonic emission with a phonon replica from graphene nanosheets deposited on
Zhaojun Tang1,2, Tingting Xu1, Sen Li1
1Department of Physics and Laboratory of Material Physics, Zhengzhou University, Zhengzhou 450001, People's Republic of China.
Abstract:
Graphene nanosheets (GNSs) were grown on a Si nanoporous pillar array (Si-NPA) via chemical vapour deposition, using a thin layer of pre-deposited Ni nanocrystallites as catalyst. GNSs were determined to be of high quality and good dispersivity, with a typical diameter size of 15 × 8 nm. Light absorption measurements showed that GNSs had an absorption band edge at 3.3 eV. They also showed sharp and regular excitonic emitting peaks in the ultraviolet and visible region (2.06-3.6 eV). Moreover, phonon replicas with long-term stability appeared with the excitonic peaks at room temperature. Temperature-dependent photoluminescence from the GNSs revealed that the excitonic emission derived from free and bound excitonic recombination. A physical model based on band energy theory was constructed to analyse the carrier transport of GNSs. The Ni nanocrystallites on Si-NPA, which acted as a metal-enhanced fluorescence substrate, were supposed to accelerate the excitonic recombination of GNSs and enhanced the measured emission intensity. Results of this study would be valuable in determining the luminescence mechanism of GNSs and could be applied in real-world optoelectronic devices.
Related Concept Videos
Emission Spectra
Phase Transitions: Sublimation and Deposition
Positron Emission Tomography
One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body...
Body Temperature
Body Temperature
The average body temperature is approximately 37°C (98.6°F) and typically ranges from 36.1–37.2°C...
Effects of Temperature on Free Energy

