In a study published in Materials, researchers synthesized an optoelectronic device from a CuFeO2/CuO/Cu nanocomposite through the combustion of copper foil coated with iron oxide nanomaterial. The proposed optoelectronic device exhibited exceptional photoresponsivity and sensitivity to light.
Significance of Semiconductors in Optoelectronic Devices
Optoelectronics studies devices that transform light into electrical current and vice versa. These devices have electronics and optical systems integrated into a single material. The chosen material must permit manipulation of electrical current and light and their interactions.
Metals are good electrical conductors, yet they prohibit the passage of light. Glass and other similar dielectric materials are electrical insulators yet may accommodate and guide light waves, such as in optical fibers. Semiconductors are between these materials since they can conduct electrical current and light waves.
The incident light generates level splitting in semiconductors that forms electron-hole pairs. The semiconductor's current density (Jph), detectivity (D), photoresponsivity (R), and photoreactor efficiency increase with the rise in electron-hole pairs.
Semiconductor optoelectronic devices can be found in applications such as optical telecommunications, military services, medical equipment, and automatic access control systems.
Metal oxides are among the most promising optoelectronic device semiconductors because of their great stability and cost-effective manufacturing. The optical behavior of these materials changes depending on their physical properties.
For example, dark-colored metal oxides with a large surface area exhibit enhanced photon absorption behavior and narrow band gaps compared to small, light-colored metal oxide semiconductors.
Copper oxide (CuO) is being considered for manufacturing optoelectronic devices due to its useful properties, such as optical absorbance in the ultraviolet, visible, and near-infrared areas and a tiny bandgap of 1.2 to 1.5 eV.
Delafossite CuFeO2 is an emerging and promising P-type semiconductor material for optoelectronics applications due to its excellent optical absorbance and moderate bandgap.
This material is prepared using advanced synthesis processes, such as 3D physical deposition, sputtering, laser and electrochemical deposition, and plasma annealing. In addition, this material is highly sensitive to light and efficiently absorbs light, indicating that it exhibits favorable optoelectronic properties.
However, the limited research on CuFeO2 as a possible optoelectronic material revealed that its current density values are low.
Investigating the Optoelectronic Properties of Nanocomposite-Based CuFeO2 Material
The direct combustion of copper foil covered with Fe2O3 in air resulted in the production of CuFeO2/CuO/Cu nanoparticles, which allowed for the simple and quick synthesis of a delafossite CuFeO2 material.
The chemical tests performed using scanning electron microscopy, transmission electron microscopy, ultraviolet, visible, and X-ray photoelectron spectroscopy verified the optical, chemical, and morphological properties.
X-ray diffraction analysis verified the successful disposition of delafossite CuFeO2 on a thin layer of Cu/CuO samples. In addition, the optical characterizations of the samples determined the optical reflectance of CuFeO2 and CuO materials.
Optoelectronic research examined the impact of light intensities (25 to 100 m.Wcm-2) and wavelengths (390 to 636 nm) on the optoelectronic device. The experiments were conducted in the dark and under fragmented light to verify the optoelectronic material's sensitivity to light irradiation.
Important Findings of the Study
The designed optoelectronic device demonstrated excellent dark and light behavior, with a current density value rose from 0.11 to 0.05 mA.cm-2 in the potential range of 1.0 to +1.0, respectively. This increase in light quality demonstrates that incident light has a significant impact on the optoelectronic device.
The optical reflectance of CuFeO2 nanoparticles was significantly superior to that of CuO nanomaterials. The bandgap values identified these increases, ranging from 1.35 to 1.38 eV, respectively.
The optoelectronic device's high sensitivity appears consistent across all current density values, regardless of the light intensity. This demonstrates that the large surface area of the designed optoelectronic material can respond to extremely low amounts of photons.
At wavelengths of 390 nm, 508 nm, and 636 nm, the current density value was equivalent to 0.033 mA.cm-2, 0.031 mA.cm-2, and finally 0.0315 mA.cm-2.
The photoresponsivity and detectivity values were found at 0.33 mA.W−1 and 7.36 × 1010 Jones at 390 nm. The measured values corroborate the developed optoelectronic device's strong light sensitivity in a broad optical range with high efficiency.
The designed optoelectronic device functions as a light detector in the ultraviolet, visible, and near-infrared ranges, with the tremendous benefit of being inexpensive under normal conditions and applicable to large areas. These benefits illustrate the potential value of employing the optoelectronic device in industrial applications.
Alkallas, F.H., Ben Gouider Trabelsi, A., Alrebdi, T.A., Ahmed, A.M., & Rabia M. (2022) Development of a Highly Efficient Optoelectronic Device Based on CuFeO2/CuO/Cu Composite Nanomaterials. Materials. https://www.mdpi.com/1996-1944/15/19/6857