Despite remarkable progress, the performance of lead halide perovskite solar cells fabricated in an inverted structure lags behind that standard architecture devices. Here, we report on a dual interfacial modification approach based incorporation large organic cations at both bottom and top interfaces active layer. Together, this leads to simultaneous improvement open-circuit voltage fill factor devices, reaching maximum values 1.184 V 85%, respectively, resulting champion device efficiency...

Point defects in metal halide perovskites play a critical role determining their properties and optoelectronic performance; however, many open questions remain unanswered. In this work, we apply impedance spectroscopy deep-level transient to characterize the ionic defect landscape methylammonium lead triiodide (MAPbI3) which were purposely introduced by fractionally changing precursor stoichiometry. Our results highlight profound influence of on electronic landscape, exemplified impact...

Deposition of perovskite films by antisolvent engineering is a highly common method employed in photovoltaics research. Herein, we report on general that allows for the fabrication efficient solar cells any via manipulation application rate. Through detailed structural, compositional, and microstructural characterization layers fabricated 14 different antisolvents, identify two key factors influence quality layer: solubility organic precursors its miscibility with host solvent(s) precursor...

Wurtzite ZnO has many potential applications in optoelectronic devices, and the hydrogenated exhibits excellent photoelectronic properties compared to undoped ZnO; however, structure of H-related defects is still unclear. In this article, effects hydrogen-plasma treatment subsequent annealing on electrical optical films were investigated by a combination Hall measurement, Raman scattering, photoluminescence. It found that two types hydrogen-related defects, namely, interstitial hydrogen...

Metal halide perovskites are promising contenders for next-generation photovoltaic applications due to their remarkable efficiency and compatibility with solution-processed fabrication. Among the various strategies control crystallinity morphology of perovskite active layer its interfaces transport layers, fabrication solar cells from precursor solutions a slight excess PbI2 has become very common. Despite this, role such is still rather controversial, lacking consensus on effect bulk...

One of the key challenges for future development efficient and stable metal halide perovskite solar cells is related to migration ions in these materials. Mobile have been linked observation hysteresis current--voltage characteristics, shown reduce device stability against degradation act as recombination centers within band gap active layer. In literature one finds a broad spread reported ionic defect parameters (e.g. activation energies) seemingly similar materials, rendering...

Efficient thermally evaporated MA-free perovskite solar cells are developed by optimising their stoichiometry and annealing procedures.

Abstract The success of metal halide perovskites in photovoltaic and light‐emitting diodes (LEDs) motivates their application as a solid‐state thin‐film laser. Various have shown optically pumped stimulated emission lasing amplified spontaneous (ASE), yet the ultimate goal electrically has not been achieved. As an essential step toward this goal, here, perovskite diode structure that simultaneously exhibits stable operation at high current density (≈1 kA cm −2 ) excited ASE (with threshold...

The mixed ionic-electronic nature of lead halide perovskites makes their performance in solar cells complex nature. Ion migration is often associated with negative impacts-such as hysteresis or device degradation-leading to significant efforts suppress ionic movement perovskite cells. In this work, we demonstrate that ion trapping at the perovskite/electron transport layer interface induces band bending, thus increasing built-in potential and open-circuit voltage device. Quantum chemical...

Abstract Four π‐extended phosphoniumfluorene electrolytes (π‐PFEs) are introduced as hole‐blocking layers (HBL) in inverted architecture planar perovskite solar cells with the structure of ITO/PEDOT:PSS/MAPbI 3 /PCBM/HBL/Ag. The deep‐lying highest occupied molecular orbital energy level π‐PFEs effectively blocks holes, decreasing contact recombination. It is demonstrated that incorporation introduces a dipole moment at PCBM/Ag interface, resulting significant enhancement built‐in potential...

The properties of charged point defects in semiconductors such as metal halide perovskites play a critical role the efficiency and stability solar cells. Still, formation migration enthalpies well entropies ionic have not yet been determined experimentally. Through impedance spectroscopy, along with quantification defect properties, we demonstrate an approach to obtain ion entropy changes different perovskite thin films. We investigate lead-based that contain cations (Cs, methylammonium...

Engineering the energetics of perovskite photovoltaic devices through deliberate introduction dipoles to control built-in potential offers an opportunity enhance their performance without need modify active layer itself. In this work, we demonstrate how incorporation molecular into bathocuproine (BCP) hole-blocking inverted solar cells improves device open-circuit voltage (VOC) and, consequently, performance. We explore a series four thiaazulenic derivatives that exhibit increasing dipole...

Abstract Metal halide perovskites are an important class of emerging semiconductors. Their charge carrier dynamics is poorly understood due to limited knowledge defect physics and recombination mechanisms. Nevertheless, classical ABC Shockley-Read-Hall (SRH) models ubiquitously applied without considering their validity. Herein, advanced technique mapping photoluminescence quantum yield (PLQY) as a function both the excitation pulse energy repetition frequency developed employed examine...

The poor stability of perovskite solar cells that are based on methylammonium (MA)‐containing compositions has triggered immense interest in the development MA‐free alternatives such as double‐cation mixed‐halide Cs x FA 1– Pb(I + Br ) 3 composition (CsFA perovskites). Although efficient this have been reported, many aspects related to film formation CsFA perovskites remain unclear. Herein, influence antisolvent application rate properties and device performance investigated. It is found...

In this work, a facile, versatile approach to control the grain size and layer porosity of perovskite films is introduced. By gradually tuning amount additive (hypophosphorous acid, HPA) in methylammonium lead triiodide (MAPbI3) precursor solution, can be enhanced by over one order magnitude regardless choice underlying or substrate. A further increase HPA results formation porous with large grains. When incorporated solar cells an inverted architecture, devices far higher open-circuit...

A domino sequence, involving a phosphinoauration and gold-catalyzed 6-endo-dig cyclization step, was developed. Starting from modular simple-to-prepare phosphadiynes, π-extended phosphoniumfluorenes were synthesized. The mechanistic proposal supported by kinetic measurements the trapping of key intermediates. These led to important conclusions for hydroarylation mechanism. Cyclic voltammetry (CV) UV/Vis spectroscopy indicated interesting properties materials science. phosphoniumfluorene...

Understanding the relationship between active material's structure and function in operational devices is key for rational engineering of next generation devices. However, this has proven elusive due to invasiveness structural characterization methods their inability penetrate multi-layered device. Here, we introduce a Correlation Clustering Imaging Method (CLIM) based on photoluminescence microscopy. CLIM offers insights into functional aspects related carrier transport, defects,...

The wide band gap methylammonium lead bromide perovskite is promising for applications in tandem solar cells and light-emitting diodes. Despite its utility, there only a limited understanding of reproducibility stability. Herein, the dependence properties, performance, shelf storage thin films devices on minute changes to precursor solution stoichiometry examined detail. Although photovoltaic based these exhibit similar initial shelf-storage depends strongly stoichiometry. While all some...

A new, low temperature method for the fabrication of γ-CsPbI 3 perovskite thin films using cesium iodide (CsI), ethane-1,2-diammonium (EDAI 2 ) and lead acetate (Pb(OAc) is developed, resulting in 16.6% efficient solar cells.

AgBiS2 nanocrystal solar cells are among the most sustainable emerging photovoltaic technologies. Their environmentally-friendly composition and low energy consumption during fabrication make them particularly attractive for future applications. However, much remains unknown about stability of these devices, in particular under operational conditions. In this study, we explore effects oxygen light on identify its dependence charge extraction layers. Normally, rate oxygen-induced degradation...

Exposure to environmental factors is generally expected cause degradation in perovskite films and solar cells. Herein, we show that with certain defect profiles can display the opposite effect, healing upon exposure oxygen under illumination. We tune iodine content of methylammonium lead triiodide from understoichiometric overstoichiometric expose them light prior addition top layers device, thereby examining dependence their photooxidative response absence storage-related chemical...