Significant Enhancement of Circular Polarization in Light Emission through Controlling Helical Pitches of Semiconductor Nanohelices.

Circularly polarized light emission (CPLE) can be potentially applied to three-dimensional displays, information storage, and biometry. However, these applications are practically limited by a low purity of circular polarization, i.e., the small optical dissymmetry factor g CPLE . Herein, glancing angle deposition (GLAD) is performed to produce inorganic nanohelices (NHs) to generate CPLE with large g CPLE values. CdSe NHs emit red CPLE with g CPLE = 0.15 at a helical pitch ( P ) ≈ 570 nm, having a 40-fold amplification of g CPLE compared to that at P ≈ 160 nm. Ceria NHs emit ultraviolet-blue CPLE with g CPLE ≈ 0.06 at P ≈ 830 nm, with a 10 3 -fold amplification compared to that at P ≈ 110 nm. Both the photoluminescence and scattering among the close-packed NHs complicatedly account for the large g CPLE values, as revealed by the numerical simulations. The GLAD-based NH-fabrication platform is devised to generate CPLE with engineerable color and large g CPLE = 10 -2 -10 -1 , shedding light on the commercialization of CPLE devices.