Hot Carrier-Induced Nonlinear Photoluminescence in a Thin Indium Tin Oxide Layer Patterned by Ga Ion Beam Milling

Abstract

This paper explores the nonlinear photoluminescence emitted by Indium Tin Oxide (ITO) thin layers patterned by focused gallium ion beam milling. Using tightly focused near-infrared femtosecond pulsed laser excitation, a broad up-converted luminescence spanning the visible spectrum is detected. The intensity of the luminescence follows a non-monotonous relationship with milling doses and can be related to the modification of the ITO electronic band structure by the implantation of Ga ions. The shape and the power dependence of the spectrum share strong similarities with nonlinear photoluminescence arising from metals. The results are consistent with a nonlinear luminescence process originating from the radiative decay of photo-generated hot carriers. The ther-1 mal coefficient relating the hot carrier temperature to the laser intensity is determined as a function of milling dose.

Nonlinear Photoluminescence from Patterned ITO Thin Films

“…Here we demonstrate the emergence of NPL emission from ITO-coated glass substrate [5]. The emission is activated by the action of a focused Ga ion beam (Ga-FIB) on the surface, which modifies the electronic band structure of the film.…”

Memristive Control of Plasmon-Mediated Nonlinear Photoluminescence in Au Nanowires

“…The illumination of metallic nanostructures by ultrashort laser pulses at near-IR wavelengths induces a broadband upconverted emission spanning the visible spectral regime. Under high-intensity femtosecond excitation, this nonlinear signal has been shown to be dominated by a thermal luminescence continuum emitted by out-of-equilibrium surface electrons with transiently elevated temperatures. − Indeed, following the absorption of the light pulse, the temperature of the electron gas at the surface of the metal can reach thousands of kelvins for about a picosecond , and radiates before equilibrating with the phonons. − This nonlinear photoluminescence (N-PL) has been studied on a wide range of plasmonic geometries and materials. ,− An important feature is the dramatic signal enhancement observed from hot-spots favored by the presence of localized resonances (e.g., at nanoparticles , ). Such local signal enhancements are observed because the luminescence emanates from hot thermal electrons generated at the surface of the metal. ,, Further, in structures sustaining surface plasmon propagation (e.g., nanowires, cavities), N-PL has been shown to be spatially distributed throughout the modal landscape. , Hence, N-PL has been a key observable to unlock ultrafast light–matter interactions, and this response has found numerous usages.…”

Wave-vector analysis of plasmon-assisted distributed nonlinear photoluminescence along Au nanowires

“…[8][9][10] This nonlinear photoluminescence (N-PL) has been studied on a wide range of plasmonic geometries and materials. 3,[11][12][13][14][15][16][17][18] An important feature is the dramatic signal enhancement observed from hot-spots favored by the presence of localized resonances (e.g. at nanoparticles 19,20 ).…”