It remains urgent to integrate conductive InSb colloidal quantum dots (CQDs) for sensitive and fast near‐infrared (NIR) photodetection applications. Herein, nanocrystallized InSb CQDs (<12 nm in diameter) have been successfully obtained via hot‐injection procedure, and demonstrated a very narrow absorption peak centered at 1406 nm with a full width at half maximum (FWHM) of 10.3 nm and a broader absorption peak at 1702 nm, indicating strong quantum‐confined effect. After integrating these InSb CQDs with [6,6]‐phenyl C₆₁‐butyric acid methyl ester (PCBM) and polymeric triphenyldiamine (poly(N,N′‐diphenylben‐zidine diphenylether), poly‐TPD) bulk junction, the obtained Si/SiO₂/InSb CQDs:PCBM:poly‐TPD/Ag photodetector has reached long‐wavelength response up to 1400 nm, fast response time (<80 ms), and superior on/off ratio. In specific, charge carriers can be effectively transported due to favorable energy alignment and interpenetrating network formed in the inorganic/organic blend films. The work provides a new strategy to synthesize high‐quality InSb CQD and reveal its starting point toward low‐cost, practical, and sensitive next‐generation NIR detection.

Although cuprous phosphide (Cu₃P) has been widely studied and applied in other fields, its photoluminescence (PL) properties are rarely investigated. Herein, we report that Cu₃P can emit near-infrared light at 750 nm. We show that the annealing and the presence of cuprous oxide can enhance the PL emission. The mechanism of the PL enhancement is the improvement of crystal quality and the formation of a space charge region. Our results provide a reference for improving the PL properties of p-type semiconductors.

Metamaterial absorbers (MMAs) with dynamic tuning features have attracted great attention recently, but most realizations to date have suffered from a decay in absorptivity as the working frequency shifts. Here, thermally tunable multi-band and ultra-broadband MMAs based on vanadium dioxide (VO₂) are proposed, with nearly no reduction in absorption during the tuning process. Simulations demonstrated that the proposed design can be switched between two independently designable multi-band frequency ranges, with the absorptivity being maintained above 99.8%. Moreover, via designing multiple adjacent absorption spectra, an ultra-broadband switchable MMA that maintains high absorptivity during the tuning process is also demonstrated. Raising the ambient temperature from 298 K to 358 K, the broadband absorptive range shifts from 1.194–2.325 THz to 0.398–1.356 THz, while the absorptivity remains above 90%. This method has potential for THz communication, smart filtering, detecting, imaging, and so forth.

Benefiting from the high modulation bandwidth (BW), low energy consumption and excellent optical performance, lead halide perovskite has attracted wide attention in visible light communication (VLC). However, the ion migration which results in mobile point defects in perovskite structures is recognized as a crucial key factor inducing the performance degradation. Here, the influence of ion migration in perovskite devices on the performance of VLC was systematically studied. The ion migration process is realized by mixing CsPbBr₃ and CsPbI₃ quantum dots, during which, the performance of the VLC system is reduced, but it can return to its initial state after stabilization. The on-off keying (OOK) modulation scheme of the perovskite light-emitting diode (LED) device was carried out, achieving a data rate of 90 Mbps.