The effect of oxygen on the efficiency of planar p-i-n metal halide perovskite solar cells with a PEDOT:PSS hole transport layer

Fully soft organic electrochemical transistor enabling direct skin-mountable electrophysiological signal amplification

Here, we propose fully soft OECTs with all soft components, including a PEDOT:PSS-based soft channel, which show substantial mechanical/electrical properties. In addition, the further demonstrated skin-mountable amplifier implies the strong potential of this work to be an innovative development in wearable electronics.

Flexible fiber-shaped hydrogen gas sensor via coupling palladium with conductive polymer gel fiber

Rational design of fiber-shaped gas sensors with both excellent mechanical properties and sensing performance is of great significance for boosting future portable and wearable sensing electronics, however, it is still a challenge. Herein, we develop a novel fiber-shaped hydrogen (H₂) sensor by directly electrochemically growing palladium (Pd) sensing layer on conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) fiber electrode. This approach produces free-standing functional fiber (PEDOT:PSS@Pd) with promising mechanical features of flexibility, light weight, knittability and high mechanical strength, and good H₂ sensing performance at room temperature. The PEDOT:PSS@Pd fiber sensor exhibits short response time of 34 (± 6) s@1% and 19 (± 4) s@4% H₂ and excellent cycling stability. In addition, the fiber sensor remains good sensing behavior under different mechanical bending states, showing potential for constructing wearable sensor devices for timely H₂ leak detection. Therefore, this work has provided a smart design strategy of fiber-based gas sensor, offering an effective sensing platform and is believed to stimulate the development of wearable electronics.

A Self-Assembled Small-Molecule-Based Hole-Transporting Material for Inverted Perovskite Solar Cells

Hybrid organic-inorganic perovskite solar cells have recently emerged as one of the most promising low-cost photovoltaic technologies. The remarkable progress of perovskite photovoltaics is closely related to advances in interfacial engineering and development of charge selective interlayers. Herein, we present the synthesis and characterization of a fused azapolyheteroaromatic small molecule, namely anthradi-7-azaindole (ADAI), with outstanding performance as a hole-transporting layer in perovskite solar cells with inverted architecture. Its molecular arrangement, induced by hydrogen-bond-directed self-assembly, favors a suitable morphology of the perovskite layer, reducing the effects of recombination as revealed by light intensity dependence, photoluminescence, and electroluminescence studies.

Highly Efficient Perovskite Solar Cells Based on a Zn2SnO4 Compact Layer

In the present work, a new reflux condensation route has been developed for synthesizing a Zn₂SnO₄ film, which was first used as a compact layer in a perovskite solar cell (PSC) and achieved an efficiency of 20.1%. The high efficiency of PSC could be contributed to the following: (i) as a compact layer in a PSC, Zn₂SnO₄ exhibits high electron mobility and has an appropriate energy band structure, resulting in the efficient extraction of carriers and transport of electrons; (ii) the surface of the FTO substrate is completely covered by a Zn₂SnO₄ compact layer, and the direct contact between a perovskite layer and FTO is prevented, leading to a significantly efficiently suppression of charge recombination. Consequently, the cell consisting of a Zn₂SnO₄ compact layer exhibits excellent photovoltaic performance.

Highly efficient Zn2SnO4 perovskite solar cells through band alignment engineering

The fine-tuning of the halide ratio in a mixed cation mixed halide perovskite leads to a device with a PCE of 20.26%.

Two Low-Cost and Efficient Hole-Transporting Materials for n-i-p Type Organic-Inorganic Hybrid Perovskite Solar Cells

The simpler the design, the better and more effective it is. Two novel conjugated triarylamine derivatives in donor-π-donor structure employing biphenyl core and pyrene core as π-bridges, which are termed as Bp-OMe and Py-OMe, have been synthesized and characterized and then applied to perovskite solar cells (PSCs) as hole-transport materials (HTMs) successfully. Using 2,2',7,7'-tetrakis(N,N-di-p-methoxy-phenylamine)-9,9'-spirobiuorene (spiro-OMeTAD) as a relative reference, Py-OMe-based PSCs showed the best power conversion efficiency (PCE) of 19.28% under AM 1.5 G illumination at 100 mW cm-2, which is comparable to that of PSCs based on spiro-OMeTAD with a best PCE of 18.57% with doping. Although Bp-OMe-based PSCs performed with relatively poor PCEs (best PCE of 15.06%) than those of Py-OMe-based PSCs, attributing to the poor planarity and hole mobility, taking the cost into consideration, Bp-OMe and Py-OMe are much more likely to be promising efficient HTMs for PSCs.