The field of photovoltaics is revolutionized in recent years by the development of two–dimensional (2D) type‐II heterostructures. These heterostructures are made up of two different materials with different electronic properties, which allows for the capture of a broader spectrum of solar energy than traditional photovoltaic devices. In this study, the potential of vanadium (V)‐doped WS2is investigated, hereafter labeled V‐WS2, in combination with air‐stable Bi2O2Se for use in high‐performance photovoltaic devices. Various techniques are used to confirm the charge transfer of these heterostructures, including photoluminescence (PL) and Raman spectroscopy, along with Kelvin probe force microscopy (KPFM). The results show that the PL is quenched by 40%, 95%, and 97% for WS2/Bi2O2Se, 0.4 at.% V‐WS2/Bi2O2Se, and 2 at.% V‐WS2/Bi2O2Se, respectively, indicating a superior charge transfer in V‐WS2/Bi2O2Se compared to pristine WS2/Bi2O2Se. The exciton binding energies for WS2/Bi2O2Se, 0.4 at.% V‐WS2/Bi2O2Se and 2 at.% V‐WS2/Bi2O2Se heterostructures are estimated to be ≈130, 100, and 80 meV, respectively, which is much lower than that for monolayer WS2. These findings confirm that by incorporating V‐doped WS2, charge transfer in WS2/Bi2O2Se heterostructures can be tuned, providing a novel light‐harvesting technique for the development of the next generation of photovoltaic devices based on V‐doped transition metal dichalcogenides (TMDCs)/Bi2O2Se.
- Award ID(s):
- 1831133
- PAR ID:
- 10176277
- Date Published:
- Journal Name:
- Nanoscale
- ISSN:
- 2040-3364
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
more » « less
Abstract -
more » « less
Abstract Exploring two dimensional (2D) materials is important for further developing the field of quantum materials. However, progress in 2D material development is limited by difficulties with their production. Specifically, freestanding 2D materials with bulk non-layered structures remain particularly challenging to prepare. Traditionally, chemical or mechanical exfoliation is employed for obtaining freestanding 2D materials, but these methods typically require layered starting materials. Here we put forth a method for obtaining thin layers of
β -Bi2O3, which has a three-dimensional covalent structure, by using chemical exfoliation. In this research, Na3Ni2BiO6was exfoliated with acid and water to obtainβ -Bi2O3nanosheets less than 10 nm in height and over 1µ m in lateral size. Our results open the possibility for further exploringβ -Bi2O3nanosheets to determine whether their properties change from the bulk to the nanoscale. Furthermore, this research may facilitate further progress in obtaining nanosheets of non-layered bulk materials using chemical exfoliation. -
more » « less
Abstract The structures of glasses in the lithium–bismuth orthoborate composition range deviate significantly from the short‐range order structure of the two crystalline end‐members. Although binary Li3BO3and BiBO3are solely of comprised trigonal orthoborate anions, all glasses formed by their combination contain four‐coordinated borate tetrahedra. We analyze the structure of (75−1.5
x )Li2O–x Bi2O3–(25+0.5x )B2O3glasses in increments ofx = 5, with11B magic‐angle spinning nuclear magnetic resonance (NMR), infrared (IR), and Raman spectroscopy. For the full series, the oxygen‐to‐boron ratio remains constant at O/B = 3:1. NMR quantifies an increase in the fraction of tetrahedral boron with increasing bismuth oxide content. Evolution of the mid‐IR profile suggests multiple types of tetrahedral boron sites. Raman spectroscopy reveals that Bi2O3tends to cluster within the lithium borate matrix when initially introduced and that this behavior transforms into a bismuthate network with increasing bismuth oxide content. In all cases, mixed Bi–O–B linkages are observed. The dual role of bismuth as network modifier and network former is likewise observed in the far IR. The glass transition temperature continuously increases with bismuth oxide content; however, the glass stability displays a maximum in the multicomponent glass ofx = 40. -
more » « less
Abstract The current study shows a new attempt to develop gamma‐ray shielding glasses. The proposed glass is a borate‐base composition modified with sodium and cadmium oxides and different concentrations of bismuth oxide. Based on the melt‐quenching technique, we prepared four glass compositions of 20NaO‐15CdO‐ (65−
x )B2O3‐x Bi2O3, wherex = 0, 10, 20, and 30 mol%. The amorphous nature of the prepared samples was confirmed by XRD. To get more details about the structure, FTIR and UV‐Vis‐NIR were performed to characterize the prepared glasses. Moreover, we used ab initio molecular dynamics simulations to create the possible structures of the new compositions, and compared with the experimental measurements. A series of shielding parameters was investigated based on the gamma‐ray emission in the range of 0.01‐10 MeV. The results revealed an improvement of the shielding parameters with increasing of Bi2O3content. The sample with the highest Bi2O3(S4) has the highestZ effand least HVL, while S1 (with no Bi2O3content) has the lowestZ effat all energy levels. The gamma‐ray transmission factor of the prepared glasses was compared with some commercial concretes. Finally, the new glasses especially with highest Bi2O3are recommended to use in gamma radiation shielding facilities. -
more » « less
Abstract Printed 2D materials, derived from solution‐processed inks, offer scalable and cost‐effective routes to mechanically flexible optoelectronics. With micrometer‐scale control and broad processing latitude, aerosol‐jet printing (AJP) is of particular interest for all‐printed circuits and systems. Here, AJP is utilized to achieve ultrahigh‐responsivity photodetectors consisting of well‐aligned, percolating networks of semiconducting MoS2nanosheets and graphene electrodes on flexible polyimide substrates. Ultrathin (≈1.2 nm thick) and high‐aspect‐ratio (≈1 μm lateral size) MoS2nanosheets are obtained by electrochemical intercalation followed by megasonic atomization during AJP, which not only aerosolizes the inks but also further exfoliates the nanosheets. The incorporation of the high‐boiling‐point solvent terpineol into the MoS2ink is critical for achieving a highly aligned and flat thin‐film morphology following AJP as confirmed by grazing‐incidence wide‐angle X‐ray scattering and atomic force microscopy. Following AJP, curing is achieved with photonic annealing, which yields quasi‐ohmic contacts and photoactive channels with responsivities exceeding 103 A W−1that outperform previously reported all‐printed visible‐light photodetectors by over three orders of magnitude. Megasonic exfoliation coupled with properly designed AJP ink formulations enables the superlative optoelectronic properties of ultrathin MoS2nanosheets to be preserved and exploited for the scalable additive manufacturing of mechanically flexible optoelectronics.
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D0NR02991B
