Absorption spectroscopy of individual cadmium selenide nanowire

We develop a technique to measure the absorption spectrum of individual nanowires with the supercontinuum laser based Fourier transform spectroscopy. It employs photocurrent of a nanowire as the signal for Fourier transform spectroscopy. We demonstrate this technique in obtaining absorption spectrum of individual cadmium selenide nanowires, and determine the nanowires absorption bandgap of 1.75 eV. This technique has high detection sensitivity. Potentially it will be able to measure absorption cross-section as small as 19 nm ² per μm for a focus laser spot of 1 μm, and could be a general method to detect the absorption spectrum of individual quasi-one-dimensional nanomaterials.