Perovskite (structure)

About: Perovskite (structure) is a research topic. Over the lifetime, 51482 publications have been published within this topic receiving 1541750 citations.

17.6% stabilized efficiency in low-temperature processed planar perovskite solar cells

Abstract: We present here a planar perovskite solar cell with a stabilized power conversion efficiency (PCE) of 17.6% at the maximum power point and a PCE of 17% extracted from quasi-static J–V with an open-circuit voltage of 1.11 V. Such excellent figures of merit can be achieved by engineering a solution-processed electron buffer layer that does not require high temperature steps. A compact thin film of perovskite absorber is grown onto a PCBM-based electron extraction layer by implementing a novel two-step procedure which preserves the soluble organic interlayer during the deposition of successive layers. We demonstrate that efficient charge extraction is the key for high steady state efficiency in perovskite solar cells with a highly integrable architecture.

Strategy of Solution-Processed All-Inorganic Heterostructure for Humidity/Temperature-Stable Perovskite Quantum Dot Light-Emitting Diodes.

Abstract: Recently, a pressing requirement of solid-state lighting sources with high performance and low cost has motivated increasing research in metal halide perovskites. However, the relatively low emission efficiency and poor operation stability of perovskite light-emitting diodes (LEDs) are still critical drawbacks. In this study, a strategy of solution-processed all-inorganic heterostructure was proposed to overcome the emission efficiency and operation stability issues facing the challenges of perovskite LEDs. Solution-processed n-ZnO nanoparticles and p-NiO are used as the carrier injectors to fabricate all-inorganic heterostructured CsPbBr3 quantum dot LEDs, and a high-efficiency green emission is achieved with maximum luminance of 6093.2 cd/m2, external quantum efficiency of 3.79%, and current efficiency of 7.96 cd/A. More importantly, the studied perovskite LEDs possess a good operation stability after a long test time in air ambient. Typically, the devices can endure a high humidity (75%, 12 h) and a hi...

dc Electrical Degradation of Perovskite‐Type Titanates: II, Single Crystals

Abstract: The resistance degradation of Al-doped, Ni-doped, and Fedoped SrTiO3 single crystals is studied as a function of the temperature and the applied dc voltage. The individual influence of the acceptor dopants is discussed. Data of the mobility of oxygen vacancies are obtained from the determination of the time evolution of the electric field distribution between the electrodes, from electrocoloration studies, and from an examination of the thermal annealing after degradation. In a numerical calculation based on the defect chemistry and transport properties of titanates, the electrocoloration process is simulated and a qualitative explanation of the degradation process is presented.

Cubic-tetragonal-orthorhombic-rhombohedral ferroelectric transitions in perovskite potassium niobate: neutron powder profile refinement of the structures

Abstract: The orthorhombic and rhombohedral structures of ferroelectric potassium niobate have been determined by neutron diffraction measurements on powdered crystals, using the profile refinement technique to analyse the data. In the orthorhombic phase at 22 "C the atomic displacements along (Oll) from the cubic perovskite positions are 6(K) = -0.006 + SA, 6(Nb) = 0,070A, S(0,) = -0.138 + 6A and 6(0,,) 6(0,,,) = -0,125 + 4A. In the rhom- bohedral phase at 230K, the displacements are along (lll); 6(K) = -0,013 i 32A, 6(Nb) = 0.078A and 6(0,) = 6(0,,) = S(O,,,) = -0,140 + 4A. As a check on the profile technique, the tetragonal structure was redetermined, and good agreement obtained with the previous single-crystal work, with displacements along (OOl) of S(K) = -0,014 + 26A, 6(Nb) = 0.063A, S(0,) = -0.117 + 4A and 6(0,,) = 6(0,,,) = 0099 + 3A. All of these transitions result from the condensation at q = 0 of soft modes in which almost rigid oxygen octahedra vibrate against the potassium and niobium atoms. Our results account for the observed changes in the spontaneous polarization of potassium niobate, and demonstrate the power of the profile refinement technique for the investigation of structural phase transitions.