On-paper microsupercapacitors (MSCs) are a key energy storage component for disposable electronics that are anticipated to essentially address the increasing global concern of electronic waste. However, nearly none of the present on-paper MSCs combine eco-friendliness with high electrochemical performance (especially the rate capacity). In this work, highly reliable conductive inks based on the ternary composite of poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS), graphene quantum dots and graphene are developed for scalable inkjet printing of compact (footprint area ≈ 20 mm 2 ) disposable MSCs on commercial paper substrates. Without any post treatment, the printed patterns attain a sheet resistance as low as 4 Ω ▫ −1 . The metal-free all-solid-state MSCs exhibit a maximum areal capacitance > 2 mF cm −2 at a high scan rate of 1000 mV s −1 , long cycle life (>95% capacitance retention after 10 000 cycles), excellent flexibility, and long service time. Remarkably, the "totally metal-free" MSC arrays are fully inkjet printed on paper substrates and also exhibit high rate performance. The life cycle assessment indicates that these printed devices have much lower eco-toxicity and global warming potential than other on-paper MSCs.

The development of new infrared (IR) nonlinear optical (NLO) materials with strong second-harmonic generation (SHG) responses and high laser-induced damage thresholds (LIDTs) is urgent but challenging. Herein, the defective diamond-like chalcogenide Hg 3 P 2 S 8 (HPS) was rationally designed and fabricated by a flexible and rigid tetrahedral motif combined strategy. HPS exhibits a phase-matching SHG response of ∼3.6 × AGS (the largest one in the reported ternary sulfides), high LIDT (∼3 × AGS), wide IR transparent region (0.43−16.3 μm), moderate birefringence (0.043 at 1064 nm), and good physicochemical stability and crystal growth habits. Theoretical analyses confirm that the large SHG effect originates from the synergistic effects between distorted HgS 4 , PS 4 , and vacancy-induced nonbonding electrons. The results indicate that HPS is a promising NLO candidate for high-power, high-efficiency laser output in the mid-IR region, which provides an insight into the exploration of new IR NLO materials.

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A new alkali metal iodate, K 2 Na(IO 3 ) 2 (I 3 O 8 ), has been synthesized using the mild hydrothermal method, which is the first example of noncentrosymmetric iodate containing isolated [IO 3 ] − and [I 3 O 8 ] − groups. To the best of our knowledge, it exhibits the largest second harmonic generation response among the iodates with two types of isolated I−O groups (7.6 × KH 2 PO 4 (KDP) @1064 nm). It also possesses a moderate birefringence (Δn) of 0.055 at 1064 nm for achieving its phase matching and a wide band gap (3.83 eV) for obtaining a high laser damage threshold, which assures that it possesses a high laser-induced damage threshold (LDT, 13 × AgGaS 2 ). These results indicate that it is a good candidate for nonlinear optical applications.