Perovskite (structure)

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

Solvent-Mediated Crystallization of CH3NH3SnI3 Films for Heterojunction Depleted Perovskite Solar Cells

Abstract: Organo-lead halide perovskite solar cells have gained enormous significance and have now achieved power conversion efficiencies of ∼20% However, the potential toxicity of lead in these systems raises environmental concerns for widespread deployment Here we investigate solvent effects on the crystallization of the lead-free methylammonium tin triiodide (CH3NH3SnI3) perovskite films in a solution growth process Highly uniform, pinhole-free perovskite films are obtained from a dimethyl sulfoxide (DMSO) solution via a transitional SnI2·3DMSO intermediate phase This high-quality perovskite film enables the realization of heterojunction depleted solar cells based on mesoporous TiO2 layer but in the absence of any hole-transporting material with an unprecedented photocurrent up to 21 mA cm–2 Charge extraction and transient photovoltage decay measurements reveal high carrier densities in the CH3NH3SnI3 perovskite device which are one order of magnitude larger than CH3NH3PbI3-based devices but with comparable

Highly Emissive Divalent Ion Doped Colloidal CsPb1–xMxBr3 Perovskite Nanocrystals through Cation Exchange

Abstract: Colloidal CsPbX3 (X = Br, Cl, and I) perovskite nanocrystals (NCs) have emerged as promising phosphors and solar cell materials due to their remarkable optoelectronic properties. These properties can be tailored by not only controlling the size and shape of the NCs but also postsynthetic composition tuning through topotactic anion exchange. In contrast, property control by cation exchange is still underdeveloped for colloidal CsPbX3 NCs. Here, we present a method that allows partial cation exchange in colloidal CsPbBr3 NCs, whereby Pb2+ is exchanged for several isovalent cations, resulting in doped CsPb1–xMxBr3 NCs (M= Sn2+, Cd2+, and Zn2+; 0 50%), sh...

Polymer-modified halide perovskite films for efficient and stable planar heterojunction solar cells

Abstract: The solution processing of polycrystalline perovskite films introduces trap states that can adversely affect their optoelectronic properties. Motivated by the use of small-molecule surfactants to improve the optoelectronic performance of perovskites, we demonstrate the use of polymers with coordinating groups to improve the performance of solution-processed semiconductor films. The use of these polymer modifiers results in a marked change in the electronic properties of the films, as measured by both carrier dynamics and overall device performance. The devices grown with the polymer poly(4-vinylpyridine) (PVP) show significantly enhanced power conversion efficiency from 16.9 ± 0.7% to 18.8 ± 0.8% (champion efficiency, 20.2%) from a reverse scan and stabilized champion efficiency from 17.5 to 19.1% [under a bias of 0.94 V and AM (air mass) 1.5-G, 1-sun illumination over 30 min] compared to controls without any passivation. Treating the perovskite film with PVP enables a VOC of up to 1.16 V, which is among the best reported for a CH3NH3PbI3 perovskite solar cell and one of the lowest voltage deficits reported for any perovskite to date. In addition, perovskite solar cells treated with PVP show a long shelf lifetime of up to 90 days (retaining 85% of the initial efficiency) and increased by a factor of more than 20 compared to those without any polymer (degrading to 85% after ~4 days). Our work opens up a new class of chemical additives for improving perovskite performance and should pave the way toward improving perovskite solar cells for high efficiency and stability.

Bulk heterojunction perovskite–PCBM solar cells with high fill factor

Abstract: An inverted bulk heterojunction perovskite–PCBM solar cell with a high fill factor of 0.82 and a power conversion efficiency of up to 16.0% was fabricated by a low-temperature two-step solution process. The cells exhibit no significant photocurrent hysteresis and their high short-circuit current density, fill factor and efficiency are attributed to the advantageous properties of the active layer, such as its high conductivity and the improved mobility and diffusion length of charge carriers. In particular, PCBM plays a critical role in improving the quality of the light-absorbing layer by filling pinholes and vacancies between perovskite grains, resulting in a film with large grains and fewer grain boundaries. Bulk heterojunction perovskite solar cells with a high fill factor are reported.

Perovskite-based solar cells: impact of morphology and device architecture on device performance

Abstract: Organic–inorganic metal halide perovskites have recently shown great potential for application in solar cells with excitingly high performances with an up-to-date NREL-certified record efficiency of 20.1%. This family of materials has demonstrated considerable prospects in achieving efficiencies comparable to or even better than those of thin film solar cells. The remarkable performances thus far seem not to be limited to any specific device architecture. Both mesoscopic and planar cells showed good device performance and this eventually leads to the inevitable comparison between both architectures. Regardless of device architecture, device performance is highly dependent on the film morphology. The factors influencing the film morphology such as the deposition method, material composition, additives and film treatment will be discussed extensively in this review. The key to obtaining good-quality film morphology and hence performance is to essentially lower the energy barrier for nucleation and to promote uniform growth of the perovskite crystals. A comparison of the material selection for various layers as well as their corresponding impact on the perovskite film and device behavior in both device architectures will be presented.