We report herein a porous supramolecular framework formed by a linear mononuclear Au(I) complex (1) via the tongue-and-groove-like joinery between the pentiptycene U-cavities (grooves) and the rod-shaped π-conjugated backbone and alkyl chains (tongues) with the assistance of C−H•••π and aurophilic interactions. The framework contains distorted tetrahedral Au 4 units, which undergo stepwise and persistent photoinduced Au(I)− Au(I) bond shortening (excited-state aurophilicity), leading to multicolored luminescence photochromism. The one-dimensional pore channels could accommodate different solvates and guests, and the guest inclusion-induced luminescence enhancement (up to 300%) and/or vapochromism are characterized. A correlation between the aurophilic bonding and the luminescence activity is uncovered by TDDFT calculations. Isostructural derivatives 2 and 3 corroborate both the robustness of the porous supramolecular assembly and the mechanisms of the stimulation-induced luminescence properties of 1. This work demonstrates the cooperation of aurophilicity and structural porosity and adaptability in achieving novel supramolecular photochemical properties.
In this paper, we describe the application of the enantiomeric compounds YLC-1−YLC-4, each featuring a bulky spiro[fluorene-9,9′-phenanthren]-10′-one moiety, as both hole-transporting materials (HTMs) and interfacial layers in both n−i−p and p−i−n perovskite solar cells (PSCs). These HTMs contain an enantiomeric mixture and a variety of core units linked to triarylamine donors to extend the degree of π-conjugation. The n−i−p PSCs incorporating YLC-1(a) exhibited a power conversion efficiency (PCE) of 19.15% under AM 1.5G conditions (100 mW cm −2 ); this value was comparable with that obtained using spiro-OMeTAD as the HTM (18.25%). We obtained efficient and stable p−i−n PSCs having the dopant-free structure indium tin oxide (ITO)/NiO x /interfacial layer (YLC)/perovskite/PC 61 BM/BCP/Ag. The presence of the spiro-based compounds YLC-1 and YLC-2 efficiently passivated the interfacial and grain boundary defects of the perovskite and enhanced the sizes of its grains, more so than did YLC-3 and YLC-4. These spiro-based YLC derivatives packed densely and functioned as Lewis bases to coordinate Pb and Ni ions in the perovskite and NiO x layers, respectively. Together, the effects of smaller grain boundaries and defect passivation of the perovskite enhanced the optoelectronic properties of the PSCs. The photoinduced charge carrier extraction in the linearly increasing voltage (photo-CELIV) curves of NiO x /YLC-1(a) showed the faster carrier transport 3.3 × 10 −3 cm 2 V −1 s −1 , which improved the carrier mobility, supporting the notion of defect passivation of the perovskite. The best-performing NiO x /YLC-1(a) device provided a short-circuit current density (J SC ) of 22.88 mA cm −2 , an open-circuit voltage (V OC ) of 1.10 V, and a fill factor (FF) of 80.93%, corresponding to an overall PCE of 20.37%. In addition, the PCEs of the NiO x /YLC-1(a) and NiO x /YLC-4(b) PSC devices underwent decays of only 98.1 and 97.0% of their original values after 41 days under an Ar atmosphere. Thus, these YLC derivatives passivated the NiO x surface and optimized the film quality of perovskites, thereby leading to superior PCEs of their respective PSCs.
A ΔΣ modulator with dual-VCO-based quantizers is proposed to enhance SFDR of the converter. To alleviate the nonlinear VCO voltage-to-frequency tuning characteristics, a shifted-averaging dual VCO architecture is proposed. Furthermore, a VCO which merges a voltage summer and a current DAC for excess loop delay compensation is designed, drastically reducing the complexity of the circuit. The measured results of the proposed modulator implemented in a 65-nm CMOS technology demonstrates a peak SNDR of 65.2 dB and a peak SFDR of 75.4 dB at 21.1-mW power, with a 20-MHz bandwidth.
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