Physical Fields Manipulation for High‐Performance Perovskite Photovoltaics

Abstract

With the efforts of researchers from all over the world, metal halide perovskite solar cells (PSCs) have been booming rapidly in recent years. Generally, perovskite films are sensitive to surrounding conditions and will be changed under the action of physical fields, resulting in lattice distortion, degradation, ion migration, and so on. In this review, the progress of physical fields manipulation in PSCs, including the electric field, magnetic field, light field, stress field, and thermal field are reviewed. On this basis, the influences of these fields on PSCs are summarized and prospected. Finally, challenges and prospective research directions on how to make better use of external-fields while minimizing the unnecessary and disruptive impacts on commercial PSCs with high-efficiency and steady output are proposed.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smll.202107556. IntroductionRecent years, metal halide perovskite solar cells (PSCs) have attracted widespread attention, and their power conversion efficiency (PCE) has been rapidly increased by more than 25%. [1] In order to obtain highly efficient photovoltaic devices, the fabrication process, the photoelectric properties of perovskite active layer, the interface contact, the electrode conductivity, and so on are all crucial. Researchers have made a lot of attempts, such as, adding dopants into the perovskite film to assist the crystallization, [2] adjusting the chemical composition of the perovskite layer to regulate its bandgap, [3] changing the preparation processes and conditions to improve the crystal quality, [4] designing

A multifunctional phosphorylcholine-based polymer reduces energy loss for efficient perovskite solar cells

“…The composition of this organic-inorganic hybrid makes it highly susceptible to various physical fields, such as light, electric, stress and thermal fields, etc. 7 As a result, defects such as vacancies, [8][9][10] interstitials, [11][12][13] anti-site substitutions, [13][14][15] and dangling bonds 16,17 generally exist on the polycrystalline film surface or grain boundaries of perovskites. These defects tend to induce charge carrier recombination, suppress the separation of electron-hole pairs, result in charge losses at the interface of the perovskite/charge transport layer, cause higher energy loss and degrade the long-term stability of the devices.…”

Rationalization of passivation strategies toward high-performance perovskite solar cells

“…99 The lattice expansion or contraction induced by strain adjusts the bond strength, changes the electron band structure, and reduces defect densities. 95,100…”

“…95 The internal sources contain the ion fitness within the perovskite lattice and the variation in lattice spacing, while the external source originates from the heteroepitaxial substrates, annealing process, and applied mechanical strain. 95,96 The internal strain (tensile and compressive strain) regulation in perovskites is often performed by modifying the A-site or X-site perovskite compositions. For example, the lattice parameters decrease, and the strain relaxes when FAPbI 3 is alloyed with MABr.…”

“…99 The lattice expansion or contraction induced by strain adjusts the bond strength, changes the electron band structure, and reduces defect densities. 95,100 Furthermore, it is found that the strain can cause a phase transformation of perovskites. Without introducing any adverse chemical or thermal effect, Kong et al applied a hydrostatic strain to precisely modulate the crystal lattice of perovskites.…”

Self‐Powered Lithium Niobate Thin‐Film Photodetectors

“…Ferroelectric LiNbO 3 possesses the unique anomalous photovoltaic effect (also known as bulk photovoltaic effect) that gives rise to the strong built-in electric field and promotes the separation of electron-hole pairs. [16][17][18] Particularly, in LNOI platform, the thickness of LiNbO 3 crystal is reduced to 100 nm-scale; as a result, the photogenerated electric field is remarkably enhanced in the much compact geometries, and the photovoltage might exceed the bandgap by several orders of magnitude. [19] Nevertheless, since the weak light absorbance of LiNbO 3 in the visible and near infrared band, LNOI has been mainly utilized to improve the performance of heterogeneously integrated material-based photodetectors, such as Si-, [20] GaAs-, [21] and graphene detectors, [22] via photovoltaic and pyroelectric effects.…”