Förster Resonance Energy Transfer in Metal Halide Perovskite: Current Status and Future Prospects.

Förster Resonance Energy Transfer (FRET) is a non-radiative energy transfer process in a donor-acceptor system and has applications in various fields, such as single-molecule investigations, biosensor creation, and deoxyribonucleic acid (DNA) mechanics research. The investigation of FRET processes in metal halide perovskites has also attracted great attention from the community. The review aims to provide an up-to-date study of FRET in the context of perovskite systems.

Multifunctional and Multicolor Perovskite-CdSe Quantum Dots Diodes for Pulse Oximetry.

A conventional pulse oximeter system is composed of two light sources with different peak emission wavelengths and a photodetector. Integrating these three independent components into one single device will absolutely simplify the system design and create a miniaturized size of the product. Here, we demonstrate a bilayer perovskite-CdSe quantum dot (hereafter perovskite-QD) diode capable of voltage-tunable green/red emission and photodetection.

Interface Engineering with Quaternary Ammonium-Based Ionic Liquids toward Efficient Blue Perovskite Light-Emitting Diodes.

Perovskite light-emitting diodes (PeLEDs) have become a hot research topic in recent years and can now achieve an external quantum efficiency (EQE) of over 22% for green and red devices. However, the efficiency of blue PeLEDs, which are essential for display applications, lags far behind their green and red counterparts. The interface of the PeLEDs has a critical influence on the carrier transport and exciton recombination dynamics, and interface engineering is considered to be an effective strategy to improve the device performance.

Lattice strain modulation toward efficient blue perovskite light-emitting diodes.

The successful implementation of perovskite light-emitting diodes (PeLEDs) in advanced displays and lighting has proven to be challenging because of the inferior performance of blue devices. Here, we point out that a strained system would lead to the quasi-degenerate energy state to enhance the excited-state transition due to the formation of double-polarized transition channel. The tensile strained structure also brings about a synergetic control of the carrier dynamics in virtue of lattice structure deformation and reduced dimensional phase regulation to promote carrier population in large bandgap domains and to realize near-unit energy transfer from the large bandgap phases to the emitter phases.

Organic Ligands Armored ZnO Enhances Efficiency and Stability of CsPbIBr Perovskite Solar Cells.

Inorganic perovskite solar cells (PSCs) have witnessed great progress in recent years due to their superior thermal stability. As a representative, CsPbIBr is attracting considerable attention as it can balance the high efficiency of CsPbI and the stability of CsPbBr. However, most research employs doped charge transport materials or applies bilayer transport layers to obtain decent performance, which vastly complicates the fabrication process and scarcely satisfies the commercial production requirement.

Methylammonium-Mediated Crystallization of Cesium-Based 2D/3D Perovskites toward High-Efficiency Light-Emitting Diodes.

Two-dimensional (2D)/three-dimensional (3D) perovskites have been successfully applied in high-efficiency light-emitting diodes (LEDs) because of their large exciton binding energy () caused by the quantum and dielectric confinements. Thermal annealing and antisolvent treatments are usually executed in order to promote the crystallization and film quality of perovskites, which add complexity to the device fabrication process. Here, the cesium-based 2D/3D perovskite was prepared by introducing ammonium halide benzamidine hydrochloride (BMCl) as the additive.

Contrasting Effects of Organic Chloride Additives on Performance of Direct and Inverted Perovskite Solar Cells.

Perovskite solar cells (PSCs) have demonstrated encouraging progress in recent years. Additive engineering, where diverse additives are incorporated into the perovskite layer, has been widely adopted to tune the perovskite grains, reduce defect density and charge recombination. Here, we observe a universal phenomenon that organic chloride additives enhance the open circuit voltage () and power conversion efficiencies (PCEs) of direct PSCs but decrease the , short-circuit current (), and PCE of inverted PSCs, regardless of the choice of charge transport materials.

Ultrashort Microwave-Pumped Real-Time Thermoacoustic Breast Tumor Imaging System.

We report the design of a real-time thermoacoustic (TA) scanner dedicated to imaging deep breast tumors and investigate its imaging performance. The TA imaging system is composed of an ultrashort microwave pulse generator and a ring transducer array with 384 elements. By vertically scanning the transducer array that encircles the breast phantom, we achieve real-time, 3D thermoacoustic imaging (TAI) with an imaging speed of 16.

Handheld Thermoacoustic Scanning System Based on a Linear-array Transducer.

To receive the information necessary for imaging, traditional microwave-induced thermoacoustic imaging systems (MITISs) use a type of circular-scanning mode using single or arc detectors. However, the use of MITISs for body scanning is complicated by restrictions in space and imaging time. A linear-array detector, the most widely used transducer in medical ultrasound imaging systems for body scanning, is a possible alternative to MITISs for scanning biological tissues, such as from the breast or limbs.

Thermoacoustic imaging over large field of view for three-dimensional breast tumor localization: a phantom study.

Purpose: Previous studies demonstrated that thermoacoustic imaging (TAI) has great potential for breast tumor detection. However, large field of view (FOV) imaging remains a long-standing challenge for three-dimensional (3D) breast tumor localization. Here, the authors propose a practical TAI system for noninvasive 3D localization of breast tumors with large FOV through the use of ultrashort microwave pulse (USMP).