Energy-saving photodetectors are the key components in future photonic systems and particularly, self-powered photoelectrochemical-type photodetectors (PEC-PDs) which depart completely from the classical solid-state junction device, have lately intrigued intensive interest to meet next-generation power-independent and environment-sensitive photodetection. Herein, we construct, for the first time, solar-blind PEC PDs based on self-assembled AlGaN nanostructures on silicon. Importantly, with the proper surface platinum (Pt) decoration, a significant boost of photon responsivity by more than an order of magnitude was achieved in the newly built AlGaN:Pt nanoarchitectures, demonstrating strikingly high responsivity of 45 mA/W and record fast response/recovery time of 47/20 ms without external power source. Such high solar-blind photodetection originates from the unparalleled material quality, fast interfacial kinetics, as well as high carrier separation efficiency which suggests that embracement of defectfree wide-bandgap semiconductor nanostructures with appropriate surface decoration offers an unprecedented opportunity for designing future energy-efficient and large-scale optoelectronic systems on silicon platform.

Carbon dots (CDs) have received tremendous attention for their excellent photoluminescence (PL) properties. However, it remains a great challenge to obtain CDs with ultraviolet (UV, 200–400 nm) emission in solid state, which requires strict control of the CDs structure and overcoming the aggregation‐caused quenching (ACQ). Herein, a new sp3 compartmentalization strategy is developed to meet these requirements, by employing acetic acid to promote fractions of sp3 bonding during the synthesis of CDs. It markedly decreases the size of sp2 conjugating units in the CDs, and shifts PL emission to the ultraviolet B (UVB) region (λmax = 308 nm). Moreover, sp2 domains are well spatially compartmentalized by sp3 domains and the ACQ effect is minimized, enabling the high quantum yield in solid state (20.2%, λex = 265 nm) with a narrow bandwidth of 24 nm and environmental robustness. The solid‐state UVB emissive CDs are highly desired for application in photonic devices. Hence, a demo of UVB light‐emitting diodes is fabricated for plant lighting, leading to a 29% increase of ascorbic acid content in the basil. Overall, a rational and efficient way to construct solid UVB‐CDs phosphors for wide applications is provided.

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Realizing high‐temperature thermal stability in thermoelectric (TE) generators is a critical challenge. In this study, a synergistic interface and surface optimization strategy is implemented to enhance Mg3Sb1.5Bi0.5 TE generator performance by employing FeCrTiMnMg thermoelectric interface materials and the MgMn‐based alloy protective coating. The competitive output power density (ω) of 1.7 W cm−2 and a conversion efficiency (η) of 13% for the single‐leg device are achieved at hot‐side temperature (Th) and cold‐side temperature (Tc) of 500 and 5 °C, respectively. An ω of 0.8 W cm−2 and η of 6% for the two‐couple TE devices with p‐type commercial Bi2Te3 are also realized, values that are competitive with the commercial Bi2Te3 device. Additionally, the single‐leg device shows a high stable η for over 100 h when the Th and Tc are 400 and 5 °C, respectively, with an change rate (Δηmax/ηmax,o) of <3%. In situ transmission electron microscopy analysis further reveals that the high stability results from the effectively sluggish interdiffusion and reduced Mg evaporation that decrease the chemical potential gradient, reduce the saturated vapor pressure, and increase the diffusion activation energy barrier. This study provides a general technique route for boosting the high‐temperature thermal stability of TE generator.

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