The basic principles of organic electroluminescence and organic light-emitting diodes arepresented.The recent progress of low molecular weight complex electroluminescent materials in sum-marized.Their photoelectronic ...The basic principles of organic electroluminescence and organic light-emitting diodes arepresented.The recent progress of low molecular weight complex electroluminescent materials in sum-marized.Their photoelectronic properties,luminescent efficiency and stability of the electrolumi-nescent devices are discussed.展开更多
Perovskite light-emitting diodes(PeLEDs)exhibit remarkable potential in the field of displays and solidstate lighting.However,blue PeLEDs,a key element for practical applications,still lag behind their green and red c...Perovskite light-emitting diodes(PeLEDs)exhibit remarkable potential in the field of displays and solidstate lighting.However,blue PeLEDs,a key element for practical applications,still lag behind their green and red counterparts,due to a combination of strong nonradiative recombination losses and unoptimized device structures.In this report,we propose a buried interface modification strategy to address these challenges by focusing on the bottom-hole transport layer(HTL)of the PeLEDs.On the one hand,a multifunctional molecule,aminoacetic acid hydrochloride(AACl),is introduced to modify the HTL/perovskite interface to regulate the perovskite crystallization.Experimental investigations and theoretical calculations demonstrate that AACl can effectively reduce the nonradiative recombination losses in bulk perovskites by suppressing the growth of low-n perovskite phases and also the losses at the bottom interface by passivating interfacial defects.On the other hand,a self-assembly nanomesh structure is ingeniously developed within the HTLs.This nanomesh structure is meticulously crafted through the blending of poly-(9,9-dioctyl-fluorene-co-N-(4-butyl phenyl)diphenylamine)and poly(n-vinyl carbazole),significantly enhancing the light outcoupling efficiency in PeLEDs.As a result,our blue PeLEDs achieve remarkable external quantum efficiencies,20.4%at 487 nm and 12.5%at 470 nm,which are among the highest reported values.Our results offer valuable insights and effective methods for achieving high-performance blue PeLEDs.展开更多
To enhance the reproducibility and scale up the synthesis of colloidal quantum dots(QDs),continuous flow synthesis is an appealing alternative to the widely used batch synthesis.Amongst other advantages,the strongly e...To enhance the reproducibility and scale up the synthesis of colloidal quantum dots(QDs),continuous flow synthesis is an appealing alternative to the widely used batch synthesis.Amongst other advantages,the strongly enhanced heat and mass transfer in small tubular reactors combined with controlled pressure can be cited.Nonetheless,the widespread use of this technique is hampered by special requirements such as the absence of solid or gaseous products and the room-temperature solubility of precursors.Therefore,the transfer of established reaction conditions from batch to flow is not straightforward and in most reported works the optical properties of the obtained QDs lag behind those prepared in batch reactions.This is also the case for PbS-based QDs,which are established near infrared(NIR)absorbers/emitters.Here we identified experimental conditions giving access to high-quality PbS core and PbS/CdS core/shell QDs obtained in an automated,easily scalable continuous flow synthesis.In particular,substituted thioureas have been selected as the sulfur source and ex-situ synthesized lead and cadmium oleate as the metal precursors,and appropriate solvent mixtures have been identified for each precursor.Highly luminescent PbS/CdS QDs emitting at the target wavelengths 940 and 1130 nm of special interest for NIR light-emitting diodes have been prepared,exhibiting a photoluminescence quantum yield up to 91%.展开更多
文摘The basic principles of organic electroluminescence and organic light-emitting diodes arepresented.The recent progress of low molecular weight complex electroluminescent materials in sum-marized.Their photoelectronic properties,luminescent efficiency and stability of the electrolumi-nescent devices are discussed.
基金supported by the National Natural Science Foundation of China(12134010,62074117,and 12174290)the support of the Key R&D program from Hubei Province(2023BAB102)+1 种基金ERC Consolidator Grant(LEAP,101045098)the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Link?ping University(Faculty Grant SFO–Mat–LiU No.2009–00971)。
文摘Perovskite light-emitting diodes(PeLEDs)exhibit remarkable potential in the field of displays and solidstate lighting.However,blue PeLEDs,a key element for practical applications,still lag behind their green and red counterparts,due to a combination of strong nonradiative recombination losses and unoptimized device structures.In this report,we propose a buried interface modification strategy to address these challenges by focusing on the bottom-hole transport layer(HTL)of the PeLEDs.On the one hand,a multifunctional molecule,aminoacetic acid hydrochloride(AACl),is introduced to modify the HTL/perovskite interface to regulate the perovskite crystallization.Experimental investigations and theoretical calculations demonstrate that AACl can effectively reduce the nonradiative recombination losses in bulk perovskites by suppressing the growth of low-n perovskite phases and also the losses at the bottom interface by passivating interfacial defects.On the other hand,a self-assembly nanomesh structure is ingeniously developed within the HTLs.This nanomesh structure is meticulously crafted through the blending of poly-(9,9-dioctyl-fluorene-co-N-(4-butyl phenyl)diphenylamine)and poly(n-vinyl carbazole),significantly enhancing the light outcoupling efficiency in PeLEDs.As a result,our blue PeLEDs achieve remarkable external quantum efficiencies,20.4%at 487 nm and 12.5%at 470 nm,which are among the highest reported values.Our results offer valuable insights and effective methods for achieving high-performance blue PeLEDs.
基金platforms of the Grenoble Instruct-ERIC center(ISBGUAR 3518 CNRSCEA-UGA-EMBL)within the Grenoble Partnership for Structural Biology(PSB)+1 种基金supported by FRISBI(ANR-10-INBS-0005-02)financed within the University Grenoble Alpes graduate school(Ecoles Universitaires de Recherche)CBH-EUR-GS(ANR-17-EURE-0003).
文摘To enhance the reproducibility and scale up the synthesis of colloidal quantum dots(QDs),continuous flow synthesis is an appealing alternative to the widely used batch synthesis.Amongst other advantages,the strongly enhanced heat and mass transfer in small tubular reactors combined with controlled pressure can be cited.Nonetheless,the widespread use of this technique is hampered by special requirements such as the absence of solid or gaseous products and the room-temperature solubility of precursors.Therefore,the transfer of established reaction conditions from batch to flow is not straightforward and in most reported works the optical properties of the obtained QDs lag behind those prepared in batch reactions.This is also the case for PbS-based QDs,which are established near infrared(NIR)absorbers/emitters.Here we identified experimental conditions giving access to high-quality PbS core and PbS/CdS core/shell QDs obtained in an automated,easily scalable continuous flow synthesis.In particular,substituted thioureas have been selected as the sulfur source and ex-situ synthesized lead and cadmium oleate as the metal precursors,and appropriate solvent mixtures have been identified for each precursor.Highly luminescent PbS/CdS QDs emitting at the target wavelengths 940 and 1130 nm of special interest for NIR light-emitting diodes have been prepared,exhibiting a photoluminescence quantum yield up to 91%.
