Solution Processed Highly Responsive UV Photodetectors from Carbon Nanodot/Silicon Heterojunctions

Abstract

Carbon nanostructures technology has recently emerged as a key enabler for next-generation optoelectronic devices working in the deep UV region due to their excitonic absorption. Here, we report the fabrication of “orange juice” derived solution processed carbon nanodots (CNDs)/n-Si heterojunction showing broadband spectral response with a peak responsivity of ∼1.25 A/W in UV (∼300 nm) wavelength. The surface topography and chemical information on synthesized CNDs via a facile synthesis route have been characterized showing the presence of surface chemical states resulting broad optical emission. The CNDs/n-Si photodiode exhibits very low dark current (∼500 pA), excellent rectification ratio (∼5 × 103), and very good photomodulation in UV region. Our device exhibits better responsivity in DUV than state-of-the-art GaN based photodetectors. Solution-processability of the devices with superior optical properties of CNDs thus pave the way for future high-performance, low-cost DUV photodetectors.

Synergistic Effects of UV Irradiation on a Flexible Ag/NCQDs-MoS2/Ag/Kapton Resistive-Switching Memory Device

“…Unprecedented multifunctional devices can be designed by synergistically integrating various functional materials at the nanoscale range while maintaining their distinct properties. − Moreover, exploring how the memristor device can be tuned with external stimuli, such as temperature, light, magnetic fields, mechanical stress, and many more, would be intriguing. ,− This exploration promises to enhance our understanding of memristor behavior and the complexities of neural interactions with the surrounding environment. Among all stimuli, light stands out as the most crucial factor for remotely tuning the RS behavior, opening the doors to the development of futuristic optofunctional devices. , In addition, ultraviolet (UV) photodetectors have numerous uses in optical communications, environmental exploration, ozone-layer monitoring, water purification, and chemical and biological investigations. − The fundamental aspects of designing UV-regulated RS memory will be a unique approach for multiple futuristic applications. Such a technology allows the controllability of resistance using both voltage and UV-light pulses.…”

Sensitive Silicon Nanowire Ultraviolet B Photodetector Induced by Leakage Mode Resonances

“…In addition, UV bandpass filters that can selectively transmit UV light are often combined with Si photodetectors, which will lead to an increased fabrication cost . On the other hand, some materials and light-trapping structures that can significantly enhance UV absorption are also used to improve the photoresponse of UV light. , However, these approaches are unfortunately not compatible with conventional Si manufacturing technology.…”

“…23 On the other hand, some materials and light-trapping structures that can significantly enhance UV absorption are also used to improve the photoresponse of UV light. 24,25 However, these approaches are unfortunately not compatible with conventional Si manufacturing technology.…”

Graphene Quantum Dot-Decorated Vertically Oriented Graphene/Germanium Heterojunctions for Near-Infrared Photodetectors

“…VOG, a vertical structure formed by the overlap of longitudinally grown graphene films, not only possesses similar electrical characteristics as graphene films but also exhibits excellent light absorption from the near-infrared (NIR) to infrared (IR) region because of the edge effects and uniform index of refraction at the interface. − The unique structural/electrical properties of VOG are advantageous to the transport of photo-generated carriers and decrease recombination on the surface . Direct growth of VOG on arbitrary substrates by plasma-assisted chemical vapor deposition (PACVD) ensures the high quality of Schottky junction and improves the device performance. , Besides, GQDs as a novel class of carbon nanomaterials have undergone tremendous development in the past few years because of the unique electronic, optical, and chemical properties in conjunction with quantum confinement and edge effects. , Compared to traditional graphene derivatives, the enhanced solubility of GQDs is ideal for solution processing, thus boosting the production yields. It has been reported that GQDs contribute to light absorption and electron transportation of optoelectrical devices. , Therefore, the combination of GQDs and VOG may produce synergistic effects in light absorption and electron transportation to improve device performance .…”

“…18,21 Besides, GQDs as a novel class of carbon nanomaterials have undergone tremendous development in the past few years because of the unique electronic, optical, and chemical properties in conjunction with quantum confinement and edge effects. 22,23 Compared to traditional graphene derivatives, the enhanced solubility of GQDs is ideal for solution processing, thus boosting the production yields. It has been reported that GQDs contribute to light absorption and electron transportation of optoelectrical devices.…”