An Environmentally Stable Organic–Inorganic Hybrid Perovskite Containing Py Cation with Low Trap-State Density

Abstract

The commonly-employed methylammonium-based perovskites are environmentally unstable, which limits their commercialization. To resolve this problem, a stable hybrid perovskite, pyrrolidinium lead iodide (PyPbI3), was synthesized successfully via a simple drop casting method. The formed PyPbI3 exhibited a hexagonal structure. It presented not only excellent phase stability, but also low trap-state density, as confirmed via the X-ray diffraction and space-charge-limited currents measurements. This novel perovskite may be applicable to perovskite photovoltaics to improve their environmental stability.

Stable FAPbI3 hydrate structure by kinetics negotiation for solar cells

“…[11][12][13] Unfortunately, the structure of FAPbI 3 experienced a phase transition at room temperature, which converted it from a cubic (a-phase) to hexagonal (d-phase) structure, resulting in a rise in bandgap from ∼1.5 eV to ∼2.5 eV. [14][15][16][17] Even worse, the presence of water molecules could accelerate such a transition, which reduced the transition time from several hundred hours to only a few hours in a nitrogen gas atmosphere, causing a signicant reduction in the PCE of the device. [18][19][20] A large amount of research has been conducted to resolve this problem.…”

Probing Surface Information of Alloy by Time of Flight-Secondary Ion Mass Spectrometer

“…Obtaining the surface/interface information of materials/devices is extremely important, as the quality of surface/interface could directly determine the material/device performance. Solar cells based on hybrid perovskite have been considered as one of the most promising candidates for next generation of photovoltaics [1][2][3]. However, perovskite solar cells exhibited instability problems even under encapsulation [4][5][6][7], i.e., the surface of function layer began to degrade within only hundreds of hours, which limited their practical applications.…”

Organic Inorganic Hybrid Perovskite Solar Cells

“…Much progress has been achieved in the commercialization of solar devices, especially perovskite solar cells, which have shown excellent transport properties and low fabrication costs [1]. The organic perovskite solar cells based on MAPbI 3 and FAPbI 3 showed a surprising power conversion efficiency (PCE) of more than 25%, as opposed to their initial PCE of 3.8% a decade ago, inspiring a new era for green energy development [2].…”

“…Even with the encapsulation, the lifetime could only be extended to several thousand hours, far from enough for the commercialization. As a result, a great deal of effort has since been devoted to trying to enhance the perovskite stability [3], such as strain engineering method, interface engineering, or doping in the A/B/X sites in the ABX 3 structure of perovskite [1][2][3]. Unfortunately, these quick trials did not extend the perovskite lifetime to any appreciable level, due not least to the debatable degradation mechanism, in particular, the influence of water molecules on the perovskite structure, in addition to the possible structural variations vis-a-vis the kinetics and thermodynamics.…”

“…Moreover, Alex F. Xu et al [2] proposed a brand-new organic perovskite structure of suitable bandgap and stability. They discovered a stable hybrid perovskite, pyrrolidinium lead iodide (PyPbI 3 ), via a simple drop casting method.…”