Performance of Surface Plasmon Resonance Sensors Using Copper/Copper Oxide Films: Influence of Thicknesses and Optical Properties

Abstract

Surface plasmon resonance sensors (SPR) using copper for sensitive parts are a competitive alternative to gold and silver. Copper oxide is a semiconductor and has a non-toxic nature. The unavoidable presence of copper oxide may be of interest as it is non-toxic, but it modifies the condition of resonance and the performance of the sensor. Therefore, the characterization of the optical properties of copper and copper oxide thin films is of interest. We propose a method to recover both the thicknesses and optical properties of copper and copper oxide from absorbance curves over the (0.9;3.5) eV range, and we use these results to numerically investigate the surface plasmon resonance of copper/copper oxide thin films. Samples of initial copper thicknesses 10, 30 and 50 nm, after nine successive oxidations, are systematically studied to simulate the signal of a Surface Plasmon Resonance setup. The results obtained from the resolution of the inverse problem of absorbance are used to discuss the performance of a copper-oxide sensor and, therefore, to evaluate the optimal thicknesses.

Fabrication and Wetting Characteristics of Copper Thin Film: An Active Layer for SPR-based Sensor Applications

“…With regards to properties, Cu-based thin lms offer excellent anti-interference characteristics and radiation resistance [9][10][11][12]. Cu-based thin lms play a crucial role in Surface Plasmon Resonance (SPR) sensors, offering several important advantages and impacts [13][14]. Cu thin lms can modulate the intensity and response of surface plasmon resonance.…”

“…Cu thin lms can modulate the intensity and response of surface plasmon resonance. The thickness of the Cu lm affects the modulation capability, with thinner lms showing more obvious regulation [13,[15][16]. This modulation capability is essential for detecting changes in refractive index and achieving high sensitivity in SPR sensors.…”

“…This modulation capability is essential for detecting changes in refractive index and achieving high sensitivity in SPR sensors. Cu thin lms are a competitive alternative to gold and silver in SPR sensors [13,[17][18]. They offer interesting properties for optics, nanotechnology, and SPR sensors [19][20].…”

“…They offer interesting properties for optics, nanotechnology, and SPR sensors [19][20]. Recent studies have demonstrated that the performance of Cu-based SPR sensors is quite similar to those using gold [13,17,21]. Cu oxide, which is often present in Cu thin lms, is a semiconductor with a non-toxic nature.…”

Nonlocal response of the planar metal layer

“…Another theoretically possible realization that can be achieved via metal-dielectric layers is an environment with a negative refractive index [21,22]. The chapter itself is the development of sensitive sensors using the specific properties of the surface plasmons [23][24][25][26]. The design of structures and their proper operation of the mentioned applications always depends on the most accurate calculations.…”