Enhanced Electroluminescence from Silicon Quantum Dots Embedded in Silicon Nitride Thin Films Coupled with Gold Nanoparticles in Light Emitting Devices

Abstract

Nowadays, the use of plasmonic metal layers to improve the photonic emission characteristics of several semiconductor quantum dots is a booming tool. In this work, we report the use of silicon quantum dots (SiQDs) embedded in a silicon nitride thin film coupled with an ultra-thin gold film (AuNPs) to fabricate light emitting devices. We used the remote plasma enhanced chemical vapor deposition technique (RPECVD) in order to grow two types of silicon nitride thin films. One with an almost stoichiometric composition, acting as non-radiative spacer; the other one, with a silicon excess in its chemical composition, which causes the formation of silicon quantum dots imbibed in the silicon nitride thin film. The ultra-thin gold film was deposited by the direct current (DC)-sputtering technique, and an aluminum doped zinc oxide thin film (AZO) which was deposited by means of ultrasonic spray pyrolysis, plays the role of the ohmic metal-like electrode. We found that there is a maximum electroluminescence (EL) enhancement when the appropriate AuNPs-spacer-SiQDs configuration is used. This EL is achieved at a moderate turn-on voltage of 11 V, and the EL enhancement is around four times bigger than the photoluminescence (PL) enhancement of the same AuNPs-spacer-SiQDs configuration. From our experimental results, we surmise that EL enhancement may indeed be due to a plasmonic coupling. This kind of silicon-based LEDs has the potential for technology transfer.

Al-Doped ZnO Thin Films with 80% Average Transmittance and 32 Ohms per Square Sheet Resistance: A Genuine Alternative to Commercial High-Performance Indium Tin Oxide

“…When the pulverized precursor solution is in (3), it is forced through a directing jet of nitrogen (N2) gas towards the surface of the substrate that is in a aluminum nitride thermal plate (4) that floats in a bath of liquid tin. The temperature of the muffle is regulated through an Autonics temperature controller (5) with solid state relay model TCN4S-24R. The drag and director flows are regulated by employing two Cole-Parmer flowmeters (6) through an Autonics temperature controller with solid state relay model TCN4S-24R to operate in the ambient to 900 °C range.…”

“…During the last decades, transparent conducting oxides (TCOs) have been considered attractive materials in different areas due to their high electrical conductivity and large transparency in the visible and near-infrared regions of the electromagnetic spectrum [1][2][3][4]. TCOs are used in a wide variety of devices, e.g., in solar cells, light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), liquid crystal displays, touch screens, photothermal conversion systems, and intelligent windows [5][6][7][8][9][10][11]. The sheet resistance required for a thin transparent electrode strictly depends on the type of application where it is implemented.…”

“…The sheet resistance required for a thin transparent electrode strictly depends on the type of application where it is implemented. For example, for touch screens, sheet resistances between 200 Ω/ and 500 Ω/ are required, while for solar cells and OLEDs, the sheet resistances must be less than 50 Ω/ together with a transmittance above 80% [5,12].…”

Design, Growth, and Characterization of Crystalline Copper Oxide p-Type Transparent Semiconductive Thin Films with Figures of Merit Suitable for Their Incorporation into Translucent Devices

“…Since the early 20th century, copper-based materials have been of interest to the research community due to their multiple properties and applications, , among which stand out their use as a catalyst, an antimicrobial agent, a possible high-temperature superconductor, , a gas sensor, and a semiconductor material with diverse applications. − Regarding its use as a semiconductor material, interest in copper oxide is rekindled due to the potential benefits of its low cost and its applications in microelectronics such as in solar cell manufacturing, , as organic light-emitting diodes, , or as an auxiliary element in a wide variety of semiconductor devices. − However, the use of copper-based materials as transparent conductive films (TCFs) is still in development.…”

Improvement in Luminous Efficacy and Thermal Performance Using Quantum Dots Spherical Shell for White Light Emitting Diodes

“…However, this traditional phosphor, possessing a narrow excitation width and broad full width at half maximum (FWHM) of about 100 nm [ 11 ], is suboptimal for WLEDs design. As quantum dots (QDs) technology experiences rapid development [ 12 , 13 , 14 ], QDs, such as, CdSe/ZnS, exhibit a narrow FWHM (~30 nm), high absorption coefficient, tunable band gap, wide color gamut, and high quantum yield of up to 80%, which renders them more suitable for LED devices [ 15 ]. Replacing the phosphor powder with QDs as the fluorescence material for LED devices has recently become a topic of interest [ 16 , 17 ].…”