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- Bera, Suman, et al.
(författare)
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Limiting Heterovalent B-Site Doping in CsPbI3 Nanocrystals : Phase and Optical Stability
- 2019
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Ingår i: ACS Energy Letters. - : AMER CHEMICAL SOC. - 2380-8195. ; 4:6, s. 1364-1369
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Tidskriftsartikel (refereegranskat)abstract
- B-site doping with various metal ions in alpha-CsPbI3 has been proven to be a potential approach in bringing phase stability to these nanocrystals. However, while the doping of various homovalent ions in replacing Pb(II) has been extensively studied, heterovalent doping was observed to be limited. To understand the impact of heterovalent doping, Sb(III) was chosen here as an effective dopant for occupying the Pb(II) position in CsPbI3 nanocrystals. Importantly, it was observed that insertion of Sb(III) also stabilized the crystal phase of these red-emitting nanocrystals, but only with limited doping. However, with more intake, the cube shape turned to platelet and therefore also reduced the stability. Details of the insights of formation of these doped nanostructures are investigated, and further, these were implemented for photovoltaic application and comparable efficiency was recorded.
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2. |
- Coughlin, Michael W., et al.
(författare)
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GROWTH on S190425z : Searching Thousands of Square Degrees to Identify an Optical or Infrared Counterpart to a Binary Neutron Star Merger with the Zwicky Transient Facility and Palomar Gattini-IR
- 2019
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 885:1
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Tidskriftsartikel (refereegranskat)abstract
- The third observing run by LVC has brought the discovery of many compact binary coalescences. Following the detection of the first binary neutron star merger in this run (LIGO/Virgo S190425z), we performed a dedicated follow-up campaign with the Zwicky Transient Facility (ZTF) and Palomar Gattini-IR telescopes. The initial skymap of this single-detector gravitational wave (GW) trigger spanned most of the sky observable from Palomar Observatory. Covering 8000 deg(2) of the initial skymap over the next two nights, corresponding to 46% integrated probability, ZTF system achieved a depth of 21 m(AB) in g- and r-bands. Palomar Gattini-IR covered 2200 square degrees in J-band to a depth of 15.5 mag, including 32% integrated probability based on the initial skymap. The revised skymap issued the following day reduced these numbers to 21% for the ZTF and 19% for Palomar Gattini-IR. We narrowed 338,646 ZTF transient ?alerts? over the first two nights of observations to 15 candidate counterparts. Two candidates, ZTF19aarykkb and ZTF19aarzaod, were particularly compelling given that their location, distance, and age were consistent with the GW event, and their early optical light curves were photometrically consistent with that of kilonovae. These two candidates were spectroscopically classified as young core-collapse supernovae. The remaining candidates were ruled out as supernovae. Palomar Gattini-IR did not identify any viable candidates with multiple detections only after merger time. We demonstrate that even with single-detector GW events localized to thousands of square degrees, systematic kilonova discovery is feasible.
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