3D organic–inorganic and all‐inorganic lead halide perovskites have been intensively pursued for resistive switching memories in recent years. Unfortunately, instability and lead toxicity are two ...foremost challenges for their large‐scale commercial applications. Dimensional reduction and composition engineering are effective means to overcome these challenges. Herein, low‐dimensional inorganic lead‐free Cs3Bi2I9 and CsBi3I10 perovskite‐like films are exploited for resistive switching memory applications. Both devices demonstrate stable switching with ultrahigh on/off ratios (≈106), ultralow operation voltages (as low as 0.12 V), and self‐compliance characteristics. 0D Cs3Bi2I9‐based device shows better retention time and larger reset voltage than the 2D CsBi3I10‐based device. Multilevel resistive switching behavior is also observed by modulating the current compliance, contributing to the device tunability. The resistive switching mechanism is hinged on the formation and rupture of conductive filaments of halide vacancies in the perovskite films, which is correlated with the formation of AgIx layers at the electrode/perovskite interface. This study enriches the library of switching materials with all‐inorganic lead‐free halide perovskites and offers new insights on tuning the operation of solution‐processed memory devices.
Instability and lead toxicity are two important challenges for the application of 3D lead halide perovskites in resistive switching memories. Dimensional reduction and composition engineering are effective means to overcome these challenges. Herein, low‐dimensional lead‐free inorganic Cs3Bi2I9 and CsBi3I10‐based devices exhibit stable switching with ultrahigh On/Off ratios (≈106) and ultralow operation voltages (as low as 0.12 V).
Organic–inorganic mixed halide perovskites have emerged as an excellent class of materials with a unique combination of optoelectronic properties, suitable for a plethora of applications ranging from ...solar cells to light‐emitting diodes and photoelectrochemical devices. Recent works have showcased hybrid perovskites for electronic applications through improvements in materials design, processing, and device stability. Herein, a comprehensive up‐to‐date review is presented on hybrid perovskite electronics with a focus on transistors and memories. These applications are supported by the fundamental material properties of hybrid perovskite semiconductors such as tunable bandgap, ambipolar charge transport, reasonable mobility, defect characteristics, and solution processability, which are highlighted first. Then, recent progresses on perovskite‐based transistors are reviewed, covering aspects of fabrication process, patterning techniques, contact engineering, 2D versus 3D material selection, and device performance. Furthermore, applications of perovskites in nonvolatile memories and artificial synaptic devices are presented. The ambient instability of hybrid perovskites and the strategies to tackle this bottleneck are also discussed. Finally, an outlook and opportunities to develop perovskite‐based electronics as a competitive and feasible technology are highlighted.
Organic–inorganic halide perovskites show high promise for electronic devices owing to exceptional electrical, optical, and structural properties. The latest breakthroughs in structural, interface, defect engineering, and pattering techniques as applied to halide perovskite transistors, memories and to improve stability issues in perovskites are reviewed. Lastly, the existing challenges and outline for future research directions are provided.
Contact engineering is a prerequisite for achieving desirable functionality and performance of semiconductor electronics, which is particularly critical for organic–inorganic hybrid halide ...perovskites due to their ionic nature and highly reactive interfaces. Although the interfaces between perovskites and charge‐transporting layers have attracted lots of attention due to the photovoltaic and light‐emitting diode applications, achieving reliable perovskite/electrode contacts for electronic devices, such as transistors and memories, remains as a bottleneck. Herein, a critical review on the elusive nature of perovskite/electrode interfaces with a focus on the interfacial electrochemistry effects is presented. The basic guidelines of electrode selection are given for establishing non‐polarized interfaces and optimal energy level alignment for perovskite materials. Furthermore, state‐of‐the‐art strategies on interface‐related electrode engineering are reviewed and discussed, which aim at achieving ohmic transport and eliminating hysteresis in perovskite devices. The role and multiple functionalities of self‐assembled monolayers that offer a unique approach toward improving perovskite/electrode contacts are also discussed. The insights on electrode engineering pave the way to advancing stable and reliable perovskite devices in diverse electronic applications.
Rational selection of electrodes plays a critical role in perovskite‐based electronics due to the high reactivity of halide perovskite materials. A comprehensive review of perovskite/electrode interfaces, as well as, state‐of‐the‐art contact engineering, which assists the development of perovskite‐based devices with inhibited interfacial reactions, ohmic carrier transport, and non‐hysteric electronic characteristics, is presented.
All-inorganic CsPbI
perovskite quantum dots have received substantial research interest for photovoltaic applications because of higher efficiency compared to solar cells using other quantum dots ...materials and the various exciting properties that perovskites have to offer. These quantum dot devices also exhibit good mechanical stability amongst various thin-film photovoltaic technologies. We demonstrate higher mechanical endurance of quantum dot films compared to bulk thin film and highlight the importance of further research on high-performance and flexible optoelectronic devices using nanoscale grains as an advantage. Specifically, we develop a hybrid interfacial architecture consisting of CsPbI
quantum dot/PCBM heterojunction, enabling an energy cascade for efficient charge transfer and mechanical adhesion. The champion CsPbI
quantum dot solar cell has an efficiency of 15.1% (stabilized power output of 14.61%), which is among the highest report to date. Building on this strategy, we further demonstrate a highest efficiency of 12.3% in flexible quantum dot photovoltaics.
Due to the potential applications in optoelectronic memories, optical control of ferroelectric domain walls has emerged as an intriguing and important topic in modern solid‐state physics. However, ...its device implementation in a single ferroelectric, such as conventional BaTiO3 or PZT ceramics, still presents huge challenges in terms of the poor material conductivity and the energy mismatch between incident photons and ferroelectric switching. Here, using the generation of photocurrent in conductive α‐In2Se3 (a van der Waals ferroelectric) with a two‐terminal planar architecture, the first demonstration of optical‐engineered ferroelectric domain wall in a non‐volatile manner for optoelectronic memory application is reported. The α‐In2Se3 device exhibits a large optical‐writing and electrical‐erasing (on/off) ratio of >104, as well as multilevel current switching upon optical excitation. The narrow direct bandgap of the multilayer α‐In2Se3 ferroelectric endows the device with broadband optical‐writing wavelengths greater than 900 nm. In addition, photonic synapses with approximate linear weight updates for neuromorphic computing are also achieved in the ferroelectric devices. This work represents a breakthrough toward technological applications of ferroelectric nanodomain engineering by light.
An optically engineered ferroelectric domain wall in a layered ferroelectric is demonstrated for optoelectronic memory applications. The device exhibits a large optical‐writing and electrical‐erasing ratio of >104, as well as multilevel current switching upon optical excitation. The optical‐writing wavelength can be greater than 900 nm. Photonic synapses with approximate linear weight updates for neuromorphic computing are also achieved in such devices.
Researchers have recently revealed that hybrid lead halide perovskites exhibit ferroelectricity, which is often associated with other physical characteristics, such as a large nonlinear optical ...response. In this work, the nonlinear optical properties of single crystal inorganic–organic hybrid perovskite CH3NH3PbBr3 are studied. By exciting the material with a 1044 nm laser, strong two‐photon absorption‐induced photoluminescence in the green spectral region is observed. Using the transmission open‐aperture Z‐scan technique, the values of the two‐photon absorption coefficient are observed to be 8.5 cm GW−1, which is much higher than that of standard two‐photon absorbing materials that are industrially used in nonlinear optical applications, such as lithium niobate (LiNbO3), LiTaO3, KTiOPO4, and KH2PO4. Such a strong two‐photon absorption effect in CH3NH3PbBr3 can be used to modulate the spectral and spatial profiles of laser pulses, as well as to reduce noise, and can be used to strongly control the intensity of incident light. In this study, the superior optical limiting, pulse reshaping, and stabilization properties of CH3NH3PbBr3 are demonstrated, opening new applications for perovskites in nonlinear optics.
The two‐photon absorption properties of CH3NH3PbBr3 are investigated by exciting the material with a 1044 nm laser. Such a strong two‐photon absorption effect can be used to modulate the spectral and spatial profiles of laser pulses. In this study, the superior optical limiting, pulse reshaping, and stabilization properties of CH3NH3PbBr3 are demonstrated.
Metal‐halide perovskites have drawn profuse attention during the past decade, owing to their excellent electrical and optical properties, facile synthesis, efficient energy conversion, and so on. ...Meanwhile, the development of information storage technologies and digital communications has fueled the demand for novel semiconductor materials. Low‐dimensional perovskites have offered a new force to propel the developments of the memory field due to the excellent physical and electrical properties associated with the reduced dimensionality. In this review, the mechanisms, properties, as well as stability and performance of low‐dimensional perovskite memories, involving both molecular‐level perovskites and structure‐level nanostructures, are comprehensively reviewed. The property–performance correlation is discussed in‐depth, aiming to present effective strategies for designing memory devices based on this new class of high‐performance materials. Finally, the existing challenges and future opportunities are presented.
Low‐dimensional halide perovskites are among the most rapidly emerging building blocks for optoelectronic applications. This review elucidates the advantages and the crucial role of molecular‐/structure‐level low‐dimensional halide perovskites in achieving high performance and enhanced stability in memory applications.
Polarizers play a key role in generating polarized light for display, imaging, and data communication, but adoption often suffers from high optical loss. Recently, due to superior optoelectronic ...properties, halide perovskites have been widely developed for lighting applications; however, highly polarized emission (polarization degree >0.8) has not yet been realized with perovskites. Herein, by incorporating inkjet printing and an anodic aluminum oxide (AAO) confinement strategy, highly ordered perovskite nanowire (NW) arrays are demonstrated for anisotropic optical applications. The optical device based on perovskite NW arrays reveals a high photoluminescence external quantum efficiency of 21.6% and emits highly polarized light with polarization degree up to 0.84. The highly polarized emission from perovskite NW arrays has potential to considerably reduce the optical loss of polarizers, which may attract great interest in developing polarized light sources for next‐generation optoelectronic applications.
By incorporating inkjet printing with anodic aluminum oxide nanoporous confinement, highly ordered perovskite nanowire arrays are fabricated, which can emit extremely polarized light with a polarization degree up to 0.84.
Hybrid organic‐inorganic halide perovskites are actively pursued for optoelectronic technologies, but the poor stability is the Achilles’ heel of these materials that hinders their applications. Very ...recently, it has been shown that lead sulfide (PbS) quantum dots (QDs) can form epitaxial interfaces with the perovskite matrix and enhance the overall stability. In this work, it is demonstrated that embedding QDs can significantly modify the transport property of pristine perovskite single crystals, endowing them with new functionalities besides being structurally robust and free from grain boundaries. Resistive switching memory devices are constructed using solution‐processed CH3NH3PbBr3 (MAPbBr3) perovskite single crystals and the QD‐embedded counterparts. It is found that QDs could significantly enhance the charge transport and reduce the current–voltage hysteresis. The pristine singe crystal device exhibits negative differential resistance, while the QD‐embedded crystals are featured with filament‐type switching behavior and much improved device stability. This study underscores the potential of QD‐embedded hybrid perovskites as a new media for advanced electronic devices.
Embedding PbS quantum dots into CH3NH3PbBr3 single crystals can significantly enhance resistive switching performance and ambient stability. In general, such perovskite/quantum dot heterostructures exhibit improved charge transport property and reduced current–voltage hysteresis, suggesting the potential for advanced optoelectronics.
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