The editorial department of Zhiguanggulian has sorted out the latest important progress of domestic and foreign research teams in Academician Huang Wei's team in 2023 , and summarized other applications of perovskite solar cells , perovskite light-emitting diodes and perovskite materials . Today, Everyone shares emerging applications of hot materials.
1. Nature Photonics: Tin-based perovskite light-emitting diodes
Although lead-based perovskite light-emitting diodes have excellent luminescence performance and efficiency, environmental problems caused by the toxicity, bioaccumulation and non-degradability of lead ions are difficult to solve. Therefore, the development of new non-lead perovskites with excellent properties is a current research hotspot.
The team of Academician Huang Wei, Professor Wang Nana and Professor Wang Jianpu of Nanjing University of Technology can suppress luminescence quenching by adding appropriate additives to the tin-based perovskite precursor, thereby obtaining a high quantum efficiency light-emitting diode. Additives (phenylethylamine hydriodate, PEAI, vitamin B1, VmB1) that can form strong chemical bonds with SnI2 are added to the tin-based perovskite precursor to achieve the regulation of the growth of tin-based perovskite films. Preparation A tin-based perovskite film with regular morphology, good crystallization and low defect density was developed. The highest luminescence quantum efficiency can reach 34% (excitation power density: ~200 mW/cm 2 ), and the average luminescence quantum efficiency is 29±3%. The external quantum efficiency of the champion infrared light-emitting diode (emission peak 894 nm) prepared based on this low-density perovskite film reached 8.3%, and the average external quantum efficiency was 6.5%, proving the good repeatability of this method.
Original link: https://www.nature.com/articles/s41566-023-01231-y
2. Nat.Communications: Functional fluorinated additives promote directional crystallization of α-FAPbI3
To date, most efficiency records for perovskite solar cells have been achieved with mixed-ion FA-based perovskites. However, small amounts of these ions can affect the operational stability of the corresponding devices. It has been shown that mixed-ion perovskites suffer phase segregation under continuous illumination. The formation of pinholes and residual PbI in perovskite films caused by volatile cationic components seriously affects the device performance under high temperature or humid conditions.
Based on this, the team of Wang Fangfang & Qin Tianshi & Huang Wei of Nanjing University of Technology designed a multifunctional fluorinated additive that suppresses the complex mesophase and promotes the directional crystallization of α-FAPbI3 . The additives further polymerize in situ during the perovskite film formation process and form a hydrogen bonding network to stabilize α-FAPbI 3 . Under continuous sunlight, the efficiency of the unencapsulated device reached 24.10%, and its efficiency remained above 95% of the initial efficiency after 1,000 hours of continuous sunlight and 2,000 hours in ambient air with a humidity of about 50%.
Original link: https://www.nature.com/articles/s41467-023-36224-6
3. Nat.Communications : Thermal polymerization additives build “mortise and tenon” structure
The hole extraction efficiency at the interface is much lower than the electron extraction efficiency, resulting in the formation and accumulation of interface space charges. Most research focuses on developing new high-temperature superconducting lasers with high hole mobility or adding interface layers to provide gradient energy levels, however, it is still impossible to effectively achieve balanced carrier extraction.
The team of Academician Huang Wei, Professor Qin Tianshi, and Associate Professor Wang Fangfang reported a thermal polymerization additive N-vinyl-2-pyrrolidone (NVP) as a polymer template in a perovskite film, and then used a traditional HTL/chlorobenzene (CB) solution The spin-coating process removes residual impurities and opens the GBs to form single perovskite particles, thereby suppressing defect-related non-radiative recombination. In addition, this process also forms a novel perovskite/HTL composite film structure, which provides a significantly larger contact area between perovskite and HTL, thereby promoting hole extraction for balanced charge transport. . The authentication efficiencies of PSCs reverse scan and forward scan are 24.55% and 24.25% respectively. Furthermore, NVP-based PSCs maintain >95% initial efficiency over 1100h according to the ISOS-L-2 scheme and have excellent durability according to the ISOS-D-3 accelerated aging test.
Original link: https://www.nature.com/articles/s41467-023-38926-3
4.Nature materials: Interstitial doping suppresses ion migration
Two-dimensional layered metal halide perovskite materials (2D-LMHPs) have become one of the most promising organic-inorganic hybrid semiconductor materials due to their excellent electronic and optical properties and high stability. To date, solution-processed two-dimensional layered metal halide perovskite 2D-LMHP thin film materials with multiple quantum wells (QWs) structures have severely hindered further development of optoelectronics.
Compared with 2D-LMHP, a two-dimensional layered metal halide perovskite material with multiple quantum wells, 2D-LMHP with pure phase quantum wells exhibits a flat energy distribution and also produces less energy or charge transfer. losses, and make it less susceptible to degradation. Therefore, it is extremely attractive to promote the development of perovskite-based devices. Recently, Hao Gu of the University of Macau, Xiang Cuichuan of the University of Macau, Junmin Xia of the Nanjing University of Posts and Telecommunications (co-author), Academician Huang Weiwei Huang, Yonghua Chen of Nanjing University of Technology, Liang Chao of Xi'an Jiaotong University, etc., published comments in Nature Review Materials article.
Original link: https://www.nature.com/articles/s41578-023-00560-2
5. AM: Flexible quantum dot light-emitting devices for multifunctional and smart applications
Quantum dot light-emitting diodes ( QLEDs ) have great potential as flexible and ultrathin electronics due to their excellent performance in terms of device efficiency, color purity / tunability in the visible region, and solution processing capabilities on various substrates. Electroluminescent ( EL ) lighting and display materials. Academician Huang Wei of Northwestern Polytechnical University, Li Fushan of Fuzhou University, and Liu Yang of Fujian Normal University conducted a review on flexible quantum dot light-emitting devices for multifunctional and intelligent applications.
Flexible QLEDs enable unlimited possibilities in the era of IoT and artificial intelligence by acting as input / output ports in wearable integrated systems. Challenges remain in developing flexible QLEDs with high performance, excellent flexibility / even stretchability, and emerging applications . The authors review the latest developments in QLEDs , including quantum dot materials, working mechanisms, flexible / stretchable strategies, and patterning strategies, and highlight their emerging multifunctional integration and smart applications, including wearable optical medical devices, pressure transmitting Sensing EL devices and neural intelligent EL devices.
Original link: https://doi.org/10.1002/adma.202210385
6. AEM: 12.3% efficiency pure zinc sulfide pyrite solar cell
Cd alloying is an effective strategy to suppress Cu-Zn antisite defects and related defect clusters to improve the device performance of pure zinc sulfide tinite Cu2ZnSnS4 (CZTS) thin film solar cells. However, the potential of cadmium alloying by doping alone without further post-heat treatment has not yet been fully realized.
Academicians Xin Hao, Huang Wei and others from Nanjing University of Posts and Telecommunications reported cadmium alloyed CZTS (Cu 2 (Zn, Cd) SnS 4 , CZCTS) through dimethyl sulfoxide (DMSO) solution and studied how the alloy concentration affects CZCTS absorption. reaction pathways, grain growth, and electronic properties of the reagents.
This study found that Cd can be incorporated into CZTS through direct phase change grain growth, thereby fully suppressing band tailing. High-quality CZCTS absorber films and high-efficiency solar cells are manufactured in a wide range of alloy concentrations. The champion CZCTS device achieved a power conversion efficiency of 12.3% at a Cd concentration of 35% without any post-heat treatment, which is an increase of more than 70% compared to CZTS's 7.0%.
Original link: https://onlinelibrary.wiley.com/doi/10.1002/aenm.202301780
7. JACS : Perovskite nanocrystal packaging solution realizes self-powered luminescent white glass
Among various phosphors, metal halide perovskite nanocrystals (PNCs) are known for their size/composition-dependent spectral tunability, high brightness (up to 100% photoluminescence quantum yields (PLQYs)), and ease of solution Unique features such as processing have proven to be an ideal choice. However, due to the ionic properties of perovskites, the mixing of different phase PNCs can easily lead to structural collapse, directly limiting their applications. Therefore, there is an urgent need to develop optically suitable and robust perovskite nanocrystals and use them in the fabrication of advanced devices.
In view of this, the research groups of Huang Wei, academician of the Chinese Academy of Sciences, and Professor Qin Tianshi of Nanjing University of Technology reported a class of dendritic ammonium ligands as hard-shell encapsulated metal halide perovskite nanocrystals ( PNCs ) to improve their stability and Inhibition of ion permeation in mixed colloidal perovskite nanocrystal solutions. The as-synthesized ligand-encapsulated PNCs significantly achieve nearly uniform photoluminescence quantum yields ( PLQYs ) and strongly resist ion exchange reactions under strong anion source attack. Stable hybrid colored PNCs were embedded in laminated glass to prepare self-powered white light glass, which simultaneously serves as the absorbing emitter of fluorescent solar concentrators ( LSCs ) and the emitter of white light glass.
Original link: https://pubs.acs.org/doi/10.1021/jacs.3c10657
8. AOM: Green polar solvent and short ligand engineering to prepare deep blue CsPbBr3 perovskite quantum dots
To date, researchers have faced significant challenges in synthesizing blue perovskite quantum dots (PQDs) with short-chain ligands, which increase polarity during the synthesis process and reduce the reaction time in common non-polar solvents. solubility in . Using polar solvents instead of non-polar solvents can solve the solution problem, but polar solvents can decompose PQDs . Therefore, the key to successfully synthesizing PQDs with short-chain ligands is to find polar solvents that can dissolve the short-chain ligands well without destroying the perovskite at the same time.
Professor Chen Shufen and Academician Huang Wei of Nanjing University of Posts and Telecommunications proposed a method to synthesize dark blue CsPbBr3 PQDs with short-chain ligands at room temperature using environmentally friendly ethyl acetate polar solvent as the solvent. The average size of the synthesized CsPbBr3 PQDs is 3.87 nm, the peak wavelength is 454nm, and the photoluminescence quantum yield is 48.4%. By interlayer modification of the hole transport layer, the deep blue perovskite light-emitting diode has a maximum external quantum efficiency of 4.39% and a half-life of 4.5 min when the maximum brightness is 72 cd m−2.
Original link: https://onlinelibrary.wiley.com/doi/10.1002/adom.202300473
9. Nano Letters: Stable electron transport layer-free perovskite solar cells
Electron transport layer-free ( ETL ) perovskite solar cells ( PSCs ) have attracted great attention due to their low cost and simplified production process . However, due to the severe recombination of carriers at the perovskite / anode interface, the performance of ETL-free PSCs is still lower compared with traditional nip structure cells .
Academician Huang Wei and Song Lin of Northwestern Polytechnical University, Li Deli of Fujian Normal University and others reported stable electron transport layer-free perovskite solar cells. The authors report a strategy to fabricate stable ETL-free FAPbI3 PSCs by in situ formation of a low-dimensional perovskite layer between FTO and perovskite. This intermediate layer enables band bending and reduced defect density in the perovskite film, as well as indirect contact and improved energy level alignment between the anode and perovskite, thereby facilitating charge carrier transport and collection, and suppressing Charge carrier recombination. The photoelectric conversion efficiency ( PCE ) of the obtained ETL-free FAPbI3 PSC exceeded 22% under ambient conditions . Furthermore, simulation results show that band bending and reduced defect density are critical for high-performance ETL-free PSCs . The simple preparation procedure in this work provides a new strategy to achieve low-cost and high-efficiency production of perovskite solar cells.