Revolutionizing semiconductor fabrication, ALD, ALE, and NBE deliver atomic-scale precision, driving unprecedented performance and scalability in next-generation miniaturized devices.

The solar cell has a poor spectral response in the UV region, which affects its power conversion efficiency (PCE). The utilization of a luminescent downshifting (LDS) layer has been suggested to improve the spectral response of the photovoltaics in the short wavelength region through photoluminescence (PL) conversion and antireflection effects, which then enhance the PCE of the solar cell. Recently, colloidal quantum dots (CQDs) or perovskite quantum dots (PQDs) have been gaining prime importance as an LDS material due to their eminent optical characteristics, such as their wide absorption band, adjustable visible emission, short PL lifetime, and near-unity quantum yields. However, the instability of QDs that occurs under certain air, heat, and moisture conditions limits its commercialization. Thus, in this review, we will focus on the physical and optical characteristics of QDs. Further, we will discuss different synthesis approaches and the stability issues of QDs. Different approaches to improve the stability of QDs will be discussed in detail alongside the recent breakthroughs in QD-based solar cells for various applications and their current challenges. We expect that this review will provide an effective gateway for researchers to fabricate LDS-layer-based solar cells.

Although vacuum‐deposited metal halide perovskite light‐emitting diodes (PeLEDs) have great promise for use in large‐area high‐color‐gamut displays, the efficiency of vacuum‐sublimed PeLEDs currently lags that of solution‐processed counterparts. In this study, highly efficient vacuum‐deposited PeLEDs are prepared through a process of optimizing the stoichiometric ratio of the sublimed precursors under high vacuum and incorporating ultrathin under‐ and upper‐layers for the perovskite emission layer (EML). In contrast to the situation in most vacuum‐deposited organic light‐emitting devices, the properties of these perovskite EMLs are highly influenced by the presence and nature of the upper‐ and presublimed materials, thereby allowing us to enhance the performance of the resulting devices. By eliminating Pb° formation and passivating defects in the perovskite EMLs, the PeLEDs achieve an outstanding external quantum efficiency (EQE) of 10.9% when applying a very smooth and flat geometry; it reaches an extraordinarily high value of 21.1% when integrating a light out‐coupling structure, breaking through the 10% EQE milestone of vacuum‐deposited PeLEDs.

In this paper, Lu₃Al₅O₁₂:Ce³⁺ and CaAlSiN₃: Eu²⁺ co-doped glass are presented as color conversion materials for white light-emitting diodes (WLEDs). Through adjusting the thickness of the glass phosphors, the chromaticity and CCT of the WLEDs follows the Planckian locus well. The WLEDs show CCT ranging from ~4000K to ~7000K with high CRI ranging from 83 to 90 due to the wide emission spectrum from the proposed glass phosphors. The glass phosphors provide an effective way to achieve chromaticity-tailorable WLEDs with high color quality for indoor lighting applications.

By using the $\text{Lu}_{3}\text{Al}_{5}\text{O}_{12}:\text{Ce}^{3+}/\text{CaAlSiN}_{3}:\text{Eu}^{2+}$ phosphor co-doped fluorescent glass as a phosphor in front of an InGaN laser diode (LD), a novel white-lighting and visible light communication (VLC) module is demonstrated. By enlarging the fluorescent glass thickness from 0.7 to 1 mm, the CCT of the generated white light is increased from 7373 to 25000 K, and the maximal illuminance is enlarged from 1306 to 1356 lux. The pure LD beam based VLC can lengthen its transmission distance from 0.5 to 16 m, associated with allowable data rate slightly decreased from 14.8 to 10.8 Gbps. When using the divergent white light as a carrier for VLC transmission, the allowable data rate upgrades from 1.6 to 4.4 Gbps within 0.5-m distance in free-space by thinning the fluorescent glass from 1 to 0.7 mm. Lengthening the white-lighting distance to 1 m for the VLC system still permits 16-QAM OFDM data transmission as high as 2.8 Gbps. Such a $\text{Lu}_{3}\text{Al}_{5}\text{O}_{12}:\text{Ce}^{3+}/\text{CaAlSiN}_{3}:\text{Eu}^{2+}$ phosphor co-doped fluorescent glass not only converts the blue LD beam for white lighting efficiently, but also preserves sufficient data capacity with acceptable signal-to-noise ratio for indoor VLC application.