Optical absorptance measurement of an individual multiwall carbon nanotube using a T type thermal probe method

Abstract

Optical absorptance is an important property of carbon nanotubes for practical applications but has rarely been accurately measured. We developed a T type thermal probe method to measure the optical absorptance of an individual multiwall carbon nanotube. In this method, one end of the carbon nanotube (CNT) is attached to the center of a platinum nanofilm in a T shape and the Pt nanofilm acts as a thermometer. A laser beam irradiates at the CNT and the absorbed laser power can be determined by measuring the average temperature rise of the Pt nanofilm based on the temperature dependence of the electric resistance. Experimental results showed that a 100-nm-diameter multiwall CNT could absorb 13.2% of the 514-nm-wavelength laser power with the laser spot diameter being 1 μm. This method is useful for determining the optical absorptance of CNTs and other one-dimensional nanostructures such as Si/Ge nanowires for various optical wavelengths in their photovoltaic, photoelectrolysis and other optical applications.

Measuring the Optical Absorption of Single Nanowires

“…Note that here the incident power is the total power coming into the cryostat (as is done in, e.g., Ref. [25,47]), not just the part of the power directly hitting the NW. This is done because in our experiments the wavelength is larger than the NW diameter, and thus the influence from diffraction cannot be ignored.…”

Laser flash Raman spectroscopy method for thermophysical characterization of 2D nanomaterials

“…However, the measurement neglected the temperature distribution and radiation heat loss of the membrane thermometers. Our previous work presented a T-type Raman spectra method [18,19] to obtain the laser absorptivity of 1D micro/ nano fibers via a nanoscale resistance thermometer and further realize comprehensive thermophysical characterization via the Raman band shift. In this T-type Raman spectra method, one end of the test fiber is attached to the center of a nanoscale Pt hot film and the other end is suspended.…”

An Integrated H-type Method to Measure Thermoelectric Properties of Two-dimensional Materials

“…The laser absorption rate is also important for nanomaterials. [14][15][16] In H-type method, the laser absorption rate of 2D material can be obtained as well. Compared with T-type method, H-type method has two sensors, and the measurement accuracy and reliability can be much improved.…”