Melanin–Perovskite Composites for Photothermal Conversion

Metal halide perovskite materials, benefiting from a combination of outstanding optoelectronic properties and low‐cost solution‐preparation processes, show tremendous potential for optoelectronics and photovoltaics. However, the nanoscale inhomogeneities of the electronic properties of perovskite materials cause a number of difficulties, such as recombination, stability, and hysteresis, all of which seriously restrict device performance. Scanning probe microscopy, as a high‐resolution imaging technique, has been widely used to connect local properties and micro‐area morphologies to overall device performance. Conductive atomic force microscopy (C‐AFM) can realize a real‐space visualization of topography coupled with optoelectronic properties on a microscopic scale and thereby is uniquely suited to probe the local effects of perovskite materials and devices. The fundamental principles, alternative operation modes, and development of C‐AFM are comprehensively reviewed, and applications in perovskite solar cells (PSCs) for electronic transport behavior, ion migration and hysteresis, ferroelectric polarization, and facet orientation investigation are discussed. A comprehensive understanding and summary of up‐to‐date applications in PSCs is beneficial to further fully exploit the potential of such an emerging technique, so as to provide a novel and effective approach for perovskite materials analysis.

Section: Applications Of C‐afm Techniquementioning

confidence: 99%

Emerging Conductive Atomic Force Microscopy for Metal Halide Perovskite Materials and Solar Cells

Zhang

et al. 2020

“…On the other hand, converting MOFs into metal (compounds)/carbon hybrid nanocomposites via high‐temperature pyrolysis have been proposed as another strategy to utilize them for electrocatalysis . During the pyrolysis process, the active metal species come from the metallic nodes in the MOF precursor, while the carbon matrices are converted from the carbonization of organic ligands.…”

mentioning

confidence: 99%

Boronization‐Induced Ultrathin 2D Nanosheets with Abundant Crystalline–Amorphous Phase Boundary Supported on Nickel Foam toward Efficient Water Splitting

Fei

Cai

et al. 2019

239

115

The conversion of crystalline metal–organic frameworks (MOFs) into metal compounds/carbon hybrid nanocomposites via pyrolysis provides a promising solution to design electrocatalysts for electrochemical water splitting. However, pyrolyzing MOFs generally involves a complex high‐temperature treatment, which can destroy the coordinated surroundings within MOFs, and as a result not taking their full advantage of their electrolysis properties. Herein, a simple and room‐temperature boronization strategy is developed to convert nickel zeolite imidazolate framework (Ni‐ZIF) nanorods into ultrathin Ni‐ZIF/NiB nanosheets with abundant crystalline–amorphous phase boundaries. The combined experiment, and theoretical calculation results disclose that the ultrathin thickness allows fast electron transfer and ensures increased exposure of surface coordinatively unsaturated active sites while the crystalline–amorphous interface elaborately changes the potential‐determining step to energetically favorable intermediates. As a result, Ni‐ZIF/NiB nanosheets supported on nickel foam (NF) require overpotentials of 67 mV for the hydrogen evolution reaction and 234 mV for the oxygen evolution reaction to achieve a current density of 10 mA cm−2. Remarkably, Ni‐ZIF/NiB@NF as a bifunctional electrocatalyst for overall water splitting enables an alkaline electrolyzer with 10 mA cm−2 at an ultralow cell voltage of 1.54 V. The present work may open a new avenue to the design of MOF‐derived composites for electrocatalysis.

“…To quantify the photothermal conversion efficiency (η PT ), we adopted continuum energy balance analysis (Methods in the Supporting Information). [ 24,25 ] The 6.0 wt% CWO/resin composite exhibits η PT of ≈32% (Figure 2e), of which the efficiency of converting infrared light into heat is ≈67% and efficiency of converting UV light into heat is ≈28% (Figure S5, Supporting Information). The efficiency of converting infrared light into heat is higher than that of conventional opaque photothermal materials such as Al 2 O 3 (≈58%) [ 26 ] and PEDOS‐C6 (≈42.5%).…”

Section: Resultsmentioning

confidence: 99%

Transparent Power‐Generating Windows Based on Solar‐Thermal‐Electric Conversion

Zhang

Huang

et al. 2021

Integrating transparent solar‐harvesting systems into windows can provide renewable on‐site energy supply without altering building aesthetics or imposing further design constraints. Transparent photovoltaics have shown great potential, but the increased transparency comes at the expense of reduced power‐conversion efficiency. Here, a new technology that overcomes this limitation by combining solar‐thermal‐electric conversion with a material's wavelength‐selective absorption is presented. A wavelength‐selective film consisting of Cs0.33WO3 and resin facilitates high visible‐light transmittance (up to 88%) and outstanding ultraviolet and infrared absorbance, thereby converting absorbed light into heat without sacrificing transparency. A prototype that couples the film with thermoelectric power generation produces an extraordinary output voltage of ≈4 V within an area of 0.01 m2 exposed to sunshine. Further optimization design and experimental verification demonstrate high conversion efficiency comparable to state‐of‐the‐art transparent photovoltaics, enriching the library of on‐site energy‐saving and transparent power generation.