Perovskite photodetectors have attracted much research and attention because of their outstanding photoelectric characteristics, such as good light harvesting capability, excellent carrier migration behavior, tunable band gap, and so on. Recently, the reported studies mainly focus on materials synthesis, device structure design, interface engineering and physical mechanism analysis to improve the device characteristics, including stability, sensitivity, response speed, device noise, etc. This paper systematically summarizes the application fields and device structures of several perovskite photodetectors, including perovskite photoconductors, perovskite photodiodes, and perovskite phototransistors. Moreover, based on their molecular structure, 3D, 2D, 1D, and 0D perovskite photodetectors are introduced in detail. The research achievements and applications of perovskite photodetectors are summarized. Eventually, the future research directions and main challenges of perovskite photodetectors are prospected, and some possible solutions are proposed. The aim of the work is to provide a new thinking direction for further improving the performance of perovskite photodetectors.
Nucleic acid aptamers, selected through the Systematic Evolution of Ligands by Exponential Enrichment (SELEX), are short nucleic acid sequences that exhibit high affinity and specificity towards diverse targets. Over the past three decades, substantial advancements have been made in both the technology and applications of nucleic acid aptamers. This review provides an in-depth analysis of the historical development and defining characteristics of aptamers, highlighting recent technological innovations in SELEX, including Capillary Electrophoresis SELEX, Microfluidic SELEX, Cell-SELEX, and others. We explore the applications of aptamers in therapeutic and targeted drug delivery, emphasizing their advantages over traditional antibodies such as cost-effectiveness, ease of synthesis, and lower immunogenicity. Key challenges such as stability, specificity, and efficient delivery are discussed, with proposed strategies for improvement including advanced chemical modifications and integration with nanotechnology. By integrating advanced technologies, aptamers hold significant promise for enhancing precision medicine and personalized therapeutic interventions, offering new avenues for the treatment of complex diseases.
Terahertz spectroscopy has unique advantages in the study of biological molecules in aqueous solutions. However, water has a strong absorption capability in the terahertz region. Reducing the amount of liquid could decrease interference with the terahertz wave, which may, however, affect the measurement accuracy. Therefore, it is particularly important to balance the amount and water content of liquid samples. In this work, a terahertz metamaterial sensor based on metallic strips is designed, fabricated, and used to detect reverse micelles. An aqueous confinement environment in reverse micelles can improve the signal-to-noise ratio of the terahertz response. Due to “water pool” trapped in reverse micelles, the DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine) solution and DOPC emulsion can successfully be identified in intensity by terahertz spectroscopy. Combined with the metamaterial sensor, an obvious frequency shift of 30 GHz can be achieved to distinguish the DOPC emulsion (5%) from the DOPC solution. This approach may provide a potential way for improving the sensitivity of detecting trace elements in a buffer solution, thus offering a valuable toolkit toward bioanalytical applications.
Nowadays, Mn-doping is considered as a promising dissolution for the heavy usage of toxic lead in CsPbX3 perovskite material. Interestingly, Mn-doping also introduces an additional photoluminescence band, which is favorable to enrich the emission gamut of this cesium lead halide. Here, a solution spraying strategy was employed for the direct preparation of CsPbxMn1−x(Br,Cl)3 film through MnCl2 doping in host CsPbBr3 material. The possible fabrication mechanism of the provided approach and the dependences of material properties on Mn-doping were investigated in detail. As the results shown, Pb was partially substituted by Mn as expected. With the ratio of PbBr2:MnCl2 increasing from 3:0 to 1:1, the obtained film separately featured green, cyan, orange-red and pink-red emission, which was caused by the energy transferring process. Moreover, the combining energy of Cs, Pb, and Mn gradually red-shifted resulted from the formation of Cs-Cl, Pb-Cl and Mn-Br coordination bonding as MnCl2 doping increased. In addition, the weight of short decay lifetime of prepared samples increased with the doping rising, which indicated a better exciton emission and less defect-related transition. The aiming of current work is to provide a new possibility for the facile preparation of Mn-doping CsPbX3 film material.
In the current work, a facile ion-solution spraying strategy was employed for one-step fabrication of CsPbBr3 perovskite thin films under atmosphere. The dependences of sample properties on annealing parameters (toleration temperature and duration time) were investigated in detail. As the results suggested, the sample prepared at 200 °C for 15 min featured better properties than others. The sample displayed a cubic phase with good crystallinity, a dense and compact morphology, a bandgap energy of 2.289 eV, and an average decay lifetime of 55.536 ns. Furthermore, the sample presented a Br-rich state, which was favorable for the carrier behavior and structure stability.