Hematene Nanoflakes: A Non-van der Waals Material with Superior Nonlinear Optical Properties

Abstract

Stable and efficient optical limiters for eye and sensor protection have been in great demand ever since the advent of high-power lasers. In this study, we report the preparation of highly stable hematene nanoflakes for optical limiting applications by a facile exfoliation method from a low-cost, non-van der Waals material. Optical and structural characterization has been carried out to confirm the structure, morphology, and composition of the hematene nanoflakes. Open aperture Z-scan measurements have been carried out in near-transparent samples (87% linear transmission at the excitation wavelength of 532 nm), using 5 ns laser pulses. Despite the high transparency of the sample, a high nonlinear absorption coefficient of up to 13.0 ± 1.1 cm GW–1 has been determined, signifying the potential of this material for fabricating highly efficient optical power limiting devices.