Operational stability is crucial for the success in large-scale application of metal halide perovskites devices. The diffusion of volatile iodide component of perovskites can induce irreversible device degradation. Here, low-dimensional diffusion barriers were introduced to increase the operational stability of highefficiency large-area PSC modules. A negligible decay was observed after 1,000 h under severe test condition for a 15% high-efficiency solar module.

Solution-gated graphene field effect transistors (SGGT) were integrated in microfluidic systems. The transfer characteristics of a SGGT with an Ag/AgCl gate electrode shifted horizontally with the change of the ionic concentration of KCl solution in the microchannel and the relationship can be fitted with the Nernst equation, which was attributed to the change of the potential drop at the Ag/AgCl electrode. Therefore the gate electrode is one important factor for the ion sensitive property of the SGGT. Then SGGTs were used as flow velocity sensors, which were based on measuring the streaming potentials in microfluidic channels. A linear relationship between the shift of the transfer curve of the SGGT and the flow velocity was obtained, indicating that the SGGT is a promising transducer for measuring flow velocity in a microchip. Since the streaming potential is influenced by the three physical quantities, including the flow velocity, the ionic strength of the fluid and the zeta potential of the substrate, the device can be used for sensing any one of the three quantities when the other two were known. It is noteworthy that SGGTs have been used for various types of chemical and biological sensors. Array of the devices integrated in multichannel microchips are expected to find many important applications in the lab-on-a-chip systems in the future.

A crucial challenge is to develop an in situ passivation treatment strategy for CsPbX3 (CPX, X=Cl, Br, and I) quantum dots (QDs) and simultaneously retain their luminous efficiency and wavelength. Here, a facile method to significantly improve the stability of the CPX QDs via in situ crystallization with the synergistic effect of 4‐bromo‐butyric acid (BBA) and oleylamine (OLA) in polar solvents including aqueous solution and a possible fundamental mechanism are proposed. Monodispersed CsPbBr3 (CPB) QDs obtained in water show high photoluminescence quantum yields (PLQYs) of 86.4 % and their PL features of CPB QDs have no significant change after being dispersed in aqueous solution for 96 h, which implies the structure of CPB QDs is unchanged. The results provide a viable design strategy to synthesize all‐inorganic perovskite CPX QDs with strong stability against the attack of polar solvents and shed more light on their surface chemistry.

of effective energy regulation strategies, which facilitates the progress in the development of white light sources. The present commercial WLEDs with high color rendering index (CRI) and tunable correlate color temperature (CCT) are usually consisting of near-ultraviolet/ blue InGaN/GaN chips combined with multiple luminescent components. [1][2][3][4][5][6] However, the fabricating technology of the WLEDs devices based on coating multiple luminescent materials on semiconductor chips is complicated. The self-absorption effects and the different properties of the multiple components usually cause a decrease in luminous efficacy and a deviation in chromaticity color over a long-working time. Therefore, single-component white light emitters, including multiple luminescence centers, are attractive for high stability in a light color and facile fabrication in large quantities of manufacture. [7][8][9] In recent years, the all-inorganic perovskites have evoked tremendous attention due to their excellent optoelectronic properties originating from the formation of selftrapped excitons (STEs) caused by the localized charge distribution and strong carrier-phonon coupling. [10][11][12] The early studies were mainly focused on the multidimensional halide perovskites with intrinsic STE emissions, including 3D (Cs 2 AgInCl 6 PLQY ≈6.5%, Cs 2 NaInCl 6 PLQY ≈7%), 2D (Cs 3 Bi 2 Br 9 PLQY ≈4.5%, Cs 3 Sb 2 Cl 9 PLQY ≈11%), and 1D (CsCu 2 I 3 PLQY ≈9%) perovskites. [13][14][15][16][17] Although these compounds show broadband emission with large Stokes shift, their low PLQYs (< 15%) seriously limit their applications. 0D metal halides of the vacancy-ordered structure have attracted extensive attention because their isolated polyhedral units promote charge recombination, thus facilitating the formation of broadband STE emissions. [18][19][20][21][22][23][24][25] It was reported that the crystals of Bi 3+ /Sb 3+ co-doped Cs 2 ZrCl 6 (PLQY ≈55%) and Bi 3+ /Te 4+ co-doped Cs 2 HfCl 6 (PLQY ≈66%) show efficient dual broad emissions with a high quantum yield, which is assigned to the good compatibility structures of the hosts as well as the effective tailoring the electronic and optical properties via induction of defects. [18][19][20][21] The perovskite compound Cs 2 SnCl 6 was regarded as an excellent host because of its nontoxicity, low cost, simple structure, good compatibility, and electronically decoupled 0D structure that favors the formation of STEs. [22][23][24][25] A new class of white-light emitters based on Bi 3+ Single-component white light emitters based on the all-inorganic perovskites will act as outstanding candidates for applications in solid-state lighting thanks to their abundant energy states for self-trapped excitons (STE) with ultra-high photoluminescence (PL) efficiency. Here, a complementary white light is realized by dual STEs emissions with blue and yellow colors in a single-component perovskite Cs 2 SnCl 6 :La 3+ microcrystal (MC). The dual emission bands centered at 450 and 560 nm are attributed to the intrinsi...

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