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Luminescent solar concentrators (LSCs) are attractive for the easy operation and high compatibility with building integrated photovoltaics due to their low cost, large-scale and applicability. However, underutilized sunlight in visible wavelengths often impedes the advance of LSCs. Here, we demonstrate an orange-emitting carbon nanodots-based LSC (O-CDs) with excitation concentrated in the visible wavelengths. The orange-emitting carbon nanodots (O-CDs) with highly localized excitonic emission are prepared via atomic condensation of doped pyrrolic nitrogen, delivering a high photoluminescence quantum yield of 80 % and a suitable Stokes shift with absorption spectrum situated in the visible region. The O-CDs are embedded in polyvinylpyrrolidone to obtain a highly transparent, stable and environmentally friendly O-CDs-based LSC. Thanks to efficient utilization of solar radiation in visible areas and well match between the emission of O-CDs and the response bands of photovoltaic cells, the O-CDs-based LSC reveals an optical conversion efficiency of 5.17 %, superior to that of most carbon nanodots-based LSCs. These results provide an effective strategy to develop carbon-based luminescent concentrated materials for architectural integrated photovoltaic technology.

As the Internet of Things (IoT) continues its pervasive influence and digital technologies increasingly weave into the fabric of daily lives, the imperative for robust security measures becomes paramount to mitigate the escalating risks to the digital landscape. Traditional anti‐counterfeiting technologies, while capable to some extent, are constrained by factors such as material toxicity, low‐security efficacy, and intricate fabrication process. Mechanoluminescent materials have shown great potential in the areas of anti‐counterfeiting and security. Here, a multicolor mechanoluminescent (ML) material (lanthanide doped Ca2B2O5) synthesized by solid‐phase reaction is reported for the first time at a relatively lower temperature of 750 °C. The ML devices are obtained by embedding ML materials into polydimethylsiloxane elastomer, allowing for stress visualization with colors ranging from blue and green to orange and red. Through elaborate co‐doping, successive and accurate stress visualizations are realized. Finally, security labels based on the lanthanide ions doped Ca2B2O5 are prepared and also demonstrated to safeguard valuable packages. This work provides a novel multicolor ML material and pioneers its use in security labels, offering a universal solution for multicolor display, information security, dynamic anti‐counterfeiting, and other potential applications within the realm of IoT. [ABSTRACT FROM AUTHOR]

Optical encryption technology attracts considerable attention in the field of information encryption, information storage, and anti‐counterfeiting. However, optical encryption based on conventional on/off mode still faces issues such as low scalability, ease of cracking, and poor storage capacity; multi‐dimensional and high storage capacity information encryption systems are thus needed. Herein, a programmable information encryption circuit system is demonstrated by constructing a delay light‐emitting diode (LED) array using multi‐color phosphorescent carbon nanodots (CNDs) with versatile lifetimes. The CNDs show adjustable luminescence wavelength and lifetime from 192 to 1148 ms. The programmable delay luminescent circuit provides an intricate framework for meticulously integrating an LED array, enabling the creation of intricate patterns or alphanumeric codes. These intricate designs are engineered to serve as a component of an encryption system, which can be deciphered and unveiled under a specific delay time range. This study demonstrates the feasibility and superiority of the system as a new type of information anti‐counterfeiting encryption technology, providing a new concept for exploring the field of integrated circuit anti‐counterfeiting and encryption. [ABSTRACT FROM AUTHOR]

Mechanoluminescence (ML) is a fascinating phenomenon with diverse applications in pressure sensing, damage detection, and stress distribution visualization. However, most ML materials exhibit instantaneous photon emission that requires real‐time recording with a photodetector, and thereby circumscribing their applicability predominantly to real‐time stress‐sensing scenarios. In this work, a novel method is introduced for non‐real‐time stress sensing utilizing Li0.1Na0.9NbO3:Pr3+ phosphor, which allows for the retrieval of pressure location and intensity even 20 days after the event. The influence of heat and pressure on the trap depth distribution is analyzed using thermoluminescence (TL) and ML measurements, and it is proved that both heat and pressure release the captured electrons in the same traps. Leveraging the intricate competition between mechanical and thermal detrapping processes, stress information can be accessed through TL imaging. Furthermore, an algorithm is proposed based on this phenomenon to authenticate the stress information. This research not only advances the fundamental understanding of ML phenomena but also introduces a novel approach for applications such as mechano‐history indicators, security papers, and advanced data storage systems. [ABSTRACT FROM AUTHOR]

Metasurface enables a new class of "meta‐optics" that can manipulate light at subwavelength scale. Despite that versatile metasurfaces have been demonstrated based on a wide range of materials, the vulnerability of conventional materials to harsh environments, i.e., low resistance to corrosion, low transparency at short wavelength, and lack of thermal/mechanical stability, greatly limit their applications in extreme conditions. Diamond is well‐known for exceptional properties, including the highest thermal conductivity, high damage resistance, extraordinary hardness, and chemical inertness. Therefore, diamond based metasurface is generally expected to benefit from its material merits for extreme use. However, the performance of diamond metasurface in harsh environments remains unexplored up to date. To address this question, this work is designed to study the suitability of single‐crystal diamond based metasurface for broadband applications under harsh environments. As an example, diamond metasurfaces with representative functionalities, including holographic wavefront‐shaping, DUV‐focusing, are investigated under high‐temperature, acid/alkali, and abrasive conditions, respectively. The findings prove the capability of diamond metasurfaces for applications in broadband and harsh conditions, which not only provides a practical and scalable scheme to encode on‐demand functionalities into diamond, but also unlocks a capable candidate to develop robust, large bandwidth, and durable meta‐optics for advanced wavefront shaping under extreme conditions. [ABSTRACT FROM AUTHOR]