Optoelectronic applications require materials both responsive to objective photons and able to transfer carriers, so new two‐dimensional (2D) semiconductors with appropriate band gaps and high ...mobilities are highly desired. A broad range of band gaps and high mobilities of a 2D semiconductor family, composed of monolayer of Group 15 elements (phosphorene, arsenene, antimonene, bismuthene) is presented. The calculated binding energies and phonon band dispersions of 2D Group 15 allotropes exhibit thermodynamic stability. The energy band gaps of 2D semiconducting Group 15 monolayers cover a wide range from 0.36 to 2.62 eV, which are crucial for broadband photoresponse. Significantly, phosphorene, arsenene, and bismuthene possess carrier mobilities as high as several thousand cm2 V−1 s−1. Combining such broad band gaps and superior carrier mobilities, 2D Group 15 monolayers are promising candidates for nanoelectronics and optoelectronics.
The attractive broad range of band gaps and high mobilities of a 2D semiconductor family, namely phosphorene, arsenene, antimonene, and bismuthene, is presented. These Group 15 monolayers have significantly varied energy band gaps, which are crucial for broadband photoresponse. More importantly, puckered phosphorene, arsenene, and buckled bismuthene possess carrier mobilities as high as several thousand cm2 V−1 s−1.
Three‐dimensional (3D) metal‐halide perovskite solar cells (PSCs) have demonstrated exceptional high efficiency. However, instability of the 3D perovskite is the main challenge for industrialization. ...Incorporation of some long organic cations into perovskite crystal to terminate the lattice, and function as moisture and oxygen passivation layer and ion migration blocking layer, is proven to be an effective method to enhance the perovskite stability. Unfortunately, this method typically sacrifices charge‐carrier extraction efficiency of the perovskites. Even in 2D–3D vertically aligned heterostructures, a spread of bandgaps in the 2D due to varying degrees of quantum confinement also results in charge‐carrier localization and carrier mobility reduction. A trade‐off between the power conversion efficiency and stability is made. Here, by introducing 2D C6H18N2O2PbI4 (EDBEPbI4) microcrystals into the precursor solution, the grain boundaries of the deposited 3D perovskite film are vertically passivated with phase pure 2D perovskite. The phases pure (inorganic layer number n = 1) 2D perovskite can minimize photogenerated charge‐carrier localization in the low‐dimensional perovskite. The dominant vertical alignment does not affect charge‐carrier extraction. Therefore, high‐efficiency (21.06%) and ultrastable (retain 90% of the initial efficiency after 3000 h in air) planar PSCs are demonstrated with these 2D–3D mixtures.
High‐efficiency (21.06%) and durable 2D–3D vertical aligned perovskite solar cells (PSCs) with phase pure 2D perovskite are demonstrated. The phase pure 2D perovskite minimizes photo‐generated charge‐carrier localization in the low‐dimensional perovskite; the dominant vertical alignment does not affect charge‐carrier extraction. The traditional constraint of trade‐off between efficiency and stability in PSC is overcome.
Inspired by the recent theoretical finding that penta-graphene, composed entirely of carbon pentagons, is dynamically and mechanically stable Proc. Natl. Acad. Sci. U. S. A., 2015, 112, 2372-2377, we ...computationally designed a new two-dimensional (2D) inorganic material, a pentagonal B2C monolayer (penta-B2C), in which each pentagon contains three boron and two carbon atoms, the C atom is four-coordinated with four B atoms, and all the B atoms are three-coordinated with two C atoms and one B atom, forming a buckled 2D network. The pentagonal B2C monolayer is semiconducting with a wide indirect band gap of 2.28 eV from HSE calculations. The absence of imaginary modes in its phonon spectrum, and the high melting point predicted by molecular dynamics (MD) simulations indicate its good stability. Interestingly, the buckled structure could be stretched to planar under 15% biaxial tensile strain, and the band gap will be strikingly reduced to 0.06 eV. The semiconducting properties of penta-B2C could also be switched to those of a metallic semiconductor under certain biaxial strains, while uniaxial strains could only tune the band gaps without changing the semiconducting characteristics.
•CCS technology lock-in risk of coal-fired power plants in China was considered.•The cost of CCS commercialization in different scenarios was evaluated.•CCS retrofit potential of coal-fired power ...plants in China was explored.•Suggestions on CCS promotion and avoiding CCS technology lock-in were put forward.
Carbon capture and storage (CCS) has been discussed intensively in China; however, the CCS technology lock-in risk has been neglected for a long time and may have a negative impact on understanding the CCS application potential. Thus, from the perspective of avoiding a technology lock-in, a learning curve model and a cost-optimization model are employed in this study to explore the total cost of CCS commercialization and the national and provincial CCS retrofit potential of coal-fired power plants in China. The results show that if the second-generation CCS technologies are not commercially applied by 2040, coal-fired power plants in China may face a huge risk of being locked in by the first-generation technologies with a retrofit potential of only 0–143.63 GW (GW = 106 kW) and a cost of 13.39 billion USD. Advancing the CCS commercialization time to 2030 can reduce the technology lock-in risk greatly and increase the CCS retrofit potential to 431.01–499.90 GW, which would cost 54.3 billion USD. Considering the cost input, the technology lock-in risk, and the CCS retrofit demand, 2035 is regarded a suitable time for CCS commercialization in China with a retrofit potential of 143.63–431.04 GW and 31.46 billion USD cost input. Moreover, at the regional level, there is a great CCS retrofit potential of coal-fired power plants in Shaanxi, Hebei, and Inner Mongolia. Policymakers should provide greater support for the second-generation CCS technologies and promote them actively in 2030–2035, especially in Shaanxi, Hebei, and Inner Mongolia, to achieve CCS commercialization and control the CO2 emissions of coal-fired power plants in China.
By means of first-principles computations, we investigated the catalytic capability of the Fe-anchored graphene oxide (Fe–GO) for CO oxidation with O2. The high-energy barrier of Fe atom diffusion on ...GO and the strong binding strength of Fe anchored on GO exclude the metal clustering problem and enhance the stability of the Fe–GO system. The Fe-anchored GO exhibits good catalytic activity for CO oxidation via the favorable Eley–Rideal (ER) mechanism with a two-step route, while the Langmuir–Hinshelwood (LH) mechanism is not kinetically favorable. The low-cost Fe-anchored GO system can be easily synthesized and serves as a promising green catalyst for low-temperature CO oxidation.
Density functional theory computations were performed to investigate the stabilities and magnetic and electronic properties of VSe2 bulk, few-layers, monolayer, and its derived nanoribbons (NRs) and ...nanotubes in both T and H phases. All these materials are ferromagnetic, but exhibit versatile electronic properties. The VSe2 bulk and few-layers in either T or H phase, and T monolayer are metallic, while the H monolayer is a semiconductor. For nanoribbons, the zigzag NRs in both T and H phases and the armchair NRs in T phase are metallic, while the armchair NRs in H phase are half-metallic. The edge hydrogenation can retain or amend the electronic property of the pristine NRs depending on the chirality and phases. Regardless of the chirality, nanotubes in T phase are half-metallic, while those in H phase are metals. These findings provide a simple and effective route to tune the electronic properties of VSe2 nanostructures in a wide range and also facilitate the design of VSe2-based nanodevices.
Mechanically driven light generation is an exciting and under‐exploited phenomenon with a variety of possible practical applications. However, the current driving mode of mechanoluminescence (ML) ...devices needs strong stimuli. Here, a flexible sensitive ML device via nanodopant elasticity modulus modification is introduced. Rigid ZnS:M2+(Mn/Cu)@Al2O3 microparticles are dispersed into soft poly(dimethylsiloxane) (PDMS) film and printed out to form flexible devices. For various flexible and sensitive scenes, SiO2 nanoparticles are adopted to adjust the elasticity modulus of the PDMS matrix. The doped nanoparticles can concentrate stress to ZnS:M2+(Mn/Cu)@Al2O3 microparticles and achieve intense ML under weak stimuli of the moving skin. The printed nano‐/microparticle‐doped matrix film can achieve skin‐driven ML, which can be adopted to present fetching augmented animations expressions. The printable ML film, amenable to large areas, low‐cost manufacturing, and mechanical softness will be versatile on stress visualization, luminescent sensors, and open definitely new functional skin with novel augmented animations expressions, the photonic skin.
A flexible, sensitive mechanoluminescence (ML) device is demonstrated via matrix elasticity modulus modification. Rigid ZnS:M2+(Mn/Cu)@Al2O3 microparticles are dispersed into soft poly(dimethylsiloxane) (PDMS) film and printed for preparing flexible devices. Via a SiO2‐nanoparticle dopant, the ML intensity for small strain is significantly increased. The ML devices achieve intense ML under the weak stimuli of moving skin, which will be significant for photonic‐skin devices.
Conductive microcables embedded in a transparent film are fabricated by inkjet printing silver‐nanoparticle ink into a liquid poly(dimethylsiloxane) (PDMS) precursor substrate. By controlling the ...spreading of the ink droplet and the rheological properties of the liquid substrate, transparent multilayer circuits composed of high‐resolution embedded cables are achieved using a commercial inkjet printer. This facile strategy provides a new avenue for inkjet printing of highly integrated and transparent electronics.
The periodic systems containing planar tetracoordinate silicon (ptSi), SiC2 silagraphene, nanotubes, and nanoribbons, were predicted by means of density functional theory (DFT) computations. In SiC2 ...silagraphene, each silicon atom is bonded by four carbon atoms in a pure plane, representing the first anti-van’t Hoff/Lebel species in the Si-containing extended system. SiC2 nanotubes, rolled up by the SiC2 silagraphene, exhibit excellent elastic properties. All these ptSi-containing nanomaterials are metallic, regardless of the chirality, tube diameter, or ribbon width. The high stabilities of these systems strongly suggest the feasibility for their experimental realizations.
In this study, we selected 10 Co-based double-atom catalysts (DACs) catalysts, namely CoMN6-gra(OH) (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn), and investigated their oxygen reduction reactions ...(ORR) catalytic performances with/without considering the magnetic coupling by means of density functional theory (DFT) calculations. It was found that CoNiN6-gra(OH), CoCuN6-gra(OH), and CoZnN6-gra(OH) exhibit good catalytic activity of ORR (with low overpotentials of 0.33, 0.34 and 0.23 V, respectively) when the magnetic coupling is considered. In particular, magnetic changes in CoMN6-gra(OH) candidates play a vital role in their ORR catalytic activity. Interestingly, the d-band center can be utilized to well rationalize the ORR catalytic activity. This work highlights the importance of considering the magnetic coupling to well predict the activity of ORR catalysts, and discloses that the manipulation of the magnetic coupling between transition metal atoms is an emerging and powerful approach for the development of high-performance electrocatalysts for ORR and other related reactions.
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