Topic
Perovskite (structure)
About: Perovskite (structure) is a research topic. Over the lifetime, 51482 publications have been published within this topic receiving 1541750 citations.
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TL;DR: Colloidal nanoplatelets with predominantly single unit cell thickness and submicron lateral dimensions are obtained, which are stable in solution and exhibit a sharp excitonic absorption feature 0.5 eV blue-shifted from that of the three-dimensional bulk MAPbBr3 phase, representing a new addition to the growing family of colloidal two-dimensional nanostructures.
Abstract: We prepare colloidal nanoplatelets of methylammonium lead bromide (MAPbBr3) perovskite and compare the optical signatures of excitons in these two-dimensional systems to spherical perovskite nanocrystals and the corresponding bulk phase. We find that excitonic features that had previously been attributed to quantum confinement in MAPbBr3 nanocrystals are in fact a property of the bulk perovskite phase. Furthermore, we find that higher-energy absorption features originate from two-dimensional nanoplatelets, which are present in the nanocrystal reaction product. Upon further purification, we obtain colloidal nanoplatelets with predominantly single unit cell thickness and submicron lateral dimensions, which are stable in solution and exhibit a sharp excitonic absorption feature 0.5 eV blue-shifted from that of the three-dimensional bulk MAPbBr3 phase, representing a new addition to the growing family of colloidal two-dimensional nanostructures.
351 citations
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TL;DR: In this article, a planar p-n homojunction perovskite solar cell was proposed to promote oriented transport of the photo-induced carriers and reduce recombination, achieving a power conversion efficiency of 21.3%.
Abstract: Perovskite solar cells (PSCs) have emerged as an attractive photovoltaic technology thanks to their outstanding power conversion efficiency (PCE). Further improvement in the device efficiency is limited by the recombination of the charge carriers in the perovskite layer even when employing heterojunction-based architectures. Here, we propose and demonstrate a p-type perovskite/n-type perovskite homojunction whose built-in electric field promotes oriented transport of the photo-induced carriers, thus reducing carrier recombination losses. By controlling the stoichiometry of the perovskite precursors, we are able to induce n-type or p-type doping. We integrate the homojunction structure in a planar PSC combining a thermally evaporated p-type perovskite layer on a solution-processed n-type perovskite layer. The PSC with a MAPbI3 homojunction achieves a PCE of 20.80% (20.5% certified PCE), whereas the PSC based on a FA0.15MA0.85PbI3 homojunction delivers a PCE of 21.38%. We demonstrate that the homojunction structure is an effective approach, beyond existing planar heterojunction PSCs, to achieve highly efficient PSCs with reduced carrier recombination losses. Carrier recombination limits the power conversion efficiency of perovskite solar cells. Here the authors construct a planar p–n homojunction perovskite solar cell to promote the oriented transport of carriers and reduce recombination, thus enabling power conversion efficiency of 21.3%.
350 citations
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TL;DR: In this article, a universal behavior in rare-earth (RE)-substituted perovskite BiFe0 3 is reported, where the structural transition from the ferroelectric rhombohedral phase to an orthorhombic phase exhibiting a double-polarization hysteresis loop and substantially enhanced electromechanical properties is found to occur independent of the rare earth dopant species.
Abstract: The discovery of a universal behavior in rare-earth (RE)-substituted perovskite BiFe0 3 is reported. The structural transition from the ferroelectric rhombohedral phase to an orthorhombic phase exhibiting a double-polarization hysteresis loop and substantially enhanced electromechanical properties is found to occur independent of the RE dopant species. The structural transition can be universally achieved by controlling the average ionic radius of the A-site cation. Using calculations based on first principles, the energy landscape of BiFe0 3 is explored, and it is proposed that the origin of the double hysteresis loop and the concomitant enhancement in the piezoelectric coefficient is an electric-field-induced transformation from a paraelectric orthorhombic phase to the polar rhombohedral phase.
350 citations
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TL;DR: In this article, a defect model is proposed to rationalize the (3+ d ) vs. log log P (O 2 ) relationship as well as the reported electronic properties between the two plateaus, which is based on the following assumptions.
350 citations
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TL;DR: A new type of 2D perovskite using 2-thiophenemethylammonium (ThMA+) as a spacer cation was developed and high photovoltaic performance as well as enhanced stability in comparison with its 3D counterpart was demonstrated.
Abstract: Two-dimensional (2D) Ruddlesden–Popper perovskites have shown great potential for application in perovskite solar cells due to their appealing environmental stability However, 2D perovskites generally show poor photovoltaic performance Here, a new type of 2D perovskite using 2-thiophenemethylammonium (ThMA+) as a spacer cation was developed and high photovoltaic performance as well as enhanced stability in comparison with its 3D counterpart was demonstrated The use of the 2D perovskite (ThMA)2(MA)n−1PbnI3n+1 (n = 3) in deposited highly oriented thin films from N,N-dimethylformamide using a methylammonium chloride (MACl) assisted film-forming technique dramatically improves the efficiency of 2D perovskite photovoltaic devices from 174% to over 15%, which is the highest efficiency for 2D perovskite (n < 6) solar cells so far The enhanced performance of the 2D perovskite devices using MACl as additive is ascribed to the growth of a dense web of nanorod-like film with near-single-crystalline quality, in
349 citations