Regarding conventional quantum dot lightemitting diodes(QLEDs)fabricated by using the spin-coating(SC)technique,voids and interstitial spaces are inevitable due to unordered quantum dots(QDs)stacking,generating device...Regarding conventional quantum dot lightemitting diodes(QLEDs)fabricated by using the spin-coating(SC)technique,voids and interstitial spaces are inevitable due to unordered quantum dots(QDs)stacking,generating device leakage current under an external bias.In the present study,we fabricated an ultra-homogeneous and highly ordered QD monolayer by adopting the Langmuir-Blodgett(LB)technique.The QD monolayer was transferred as a emissive layer with a horizontal lifting(HL)method to a red QLED,which exhibited high performance with an external quantum efficiency(EQE)of 19.0% and lifetime(T_(95)@100 cd m^(-2))of13,324 h.When compared with the SC-based device,the EQE and lifetime were improved by 15% and 183% due to the compact and ordered QD monolayer that lowered the leakage current.Moreover,white QLEDs with stacked QD monolayers could be obtained at a low voltage of 4 V because LB technique is an organic-solvent-free approach avoiding interlayer mixing and controlling the QD layer thickness precisely.In addition,we successfully fabricated an ultra-homogeneous large-area QD monolayer on a rectangular substrate with a size of 9 cm×5 cm,indicating the promising size scalability of the LB-HL strategy.展开更多
Recently,solution-processed quantum dot lightemitting diodes(QLEDs)have emerged as a promising candidate for next-generation lighting and display devices.However,when given a constant voltage or current,the QLEDs need...Recently,solution-processed quantum dot lightemitting diodes(QLEDs)have emerged as a promising candidate for next-generation lighting and display devices.However,when given a constant voltage or current,the QLEDs need a certain working time to reach their maximum brightness.Such positive aging challenge,dramatically reducing the response speed of the device and causing a luminescence delay,is urgent to be investigated and resolved.In the current work,we introduce a charge-storage layer architecture by inserting copper(I)thiocyanate(CuSCN)between the organic holeinjection layer and hole-transport layer.The extracted holes will be released during the next electrical signal stimulation to increase the efficiency of charge transport.As a result,the response speed of the QLEDs is improved by an order of magnitude.In addition,by inserting an inorganic CuSCN layer,the efficiency,lifetime,and environmental stability of red/green/blue full-color QLEDs are enhanced simultaneously.Moreover,this work provides a generic strategy for the fabrication of fast-response and high-efficiency full-color QLEDs without luminescence delay,which plays a critical role in the practical industrialization of QLEDs.展开更多
Interactive display devices integrating multiple functions have become a development trend of display technology.The excellent luminescence properties of perovskite quantum dots(PQDs)make it an ideal luminescent mater...Interactive display devices integrating multiple functions have become a development trend of display technology.The excellent luminescence properties of perovskite quantum dots(PQDs)make it an ideal luminescent material for the next generation of wide-color gamut displays.Here we design and fabricate dual-function light-sensing/displaying light-emitting devices based on PQDs.The devices can display information as an output port,and simultaneously sense outside light signals as an input port and modulate the display information in a non-contact mode.The dual functions were attributed to the device designs:(1)the hole transport layer in the devices also acts as the light-sensing layer to absorb outside light signals;(2)the introduced hole trapping layer interface can trap holes originating from the light-sensing layer,and thus tune the charge transport properties and the light-emitting intensities.The sensing and display behavior of the device can be further modulated by light signals with different time and space information.This fusion of sensing and display functions has broad prospects in non-contact interactive screens and communication ports.展开更多
基金supported by the National Natural Science Foundation of China(62075043)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZZ126)。
文摘Regarding conventional quantum dot lightemitting diodes(QLEDs)fabricated by using the spin-coating(SC)technique,voids and interstitial spaces are inevitable due to unordered quantum dots(QDs)stacking,generating device leakage current under an external bias.In the present study,we fabricated an ultra-homogeneous and highly ordered QD monolayer by adopting the Langmuir-Blodgett(LB)technique.The QD monolayer was transferred as a emissive layer with a horizontal lifting(HL)method to a red QLED,which exhibited high performance with an external quantum efficiency(EQE)of 19.0% and lifetime(T_(95)@100 cd m^(-2))of13,324 h.When compared with the SC-based device,the EQE and lifetime were improved by 15% and 183% due to the compact and ordered QD monolayer that lowered the leakage current.Moreover,white QLEDs with stacked QD monolayers could be obtained at a low voltage of 4 V because LB technique is an organic-solvent-free approach avoiding interlayer mixing and controlling the QD layer thickness precisely.In addition,we successfully fabricated an ultra-homogeneous large-area QD monolayer on a rectangular substrate with a size of 9 cm×5 cm,indicating the promising size scalability of the LB-HL strategy.
基金financially supported by the National Natural Science Foundation of China(62075043)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZZ126)。
文摘Recently,solution-processed quantum dot lightemitting diodes(QLEDs)have emerged as a promising candidate for next-generation lighting and display devices.However,when given a constant voltage or current,the QLEDs need a certain working time to reach their maximum brightness.Such positive aging challenge,dramatically reducing the response speed of the device and causing a luminescence delay,is urgent to be investigated and resolved.In the current work,we introduce a charge-storage layer architecture by inserting copper(I)thiocyanate(CuSCN)between the organic holeinjection layer and hole-transport layer.The extracted holes will be released during the next electrical signal stimulation to increase the efficiency of charge transport.As a result,the response speed of the QLEDs is improved by an order of magnitude.In addition,by inserting an inorganic CuSCN layer,the efficiency,lifetime,and environmental stability of red/green/blue full-color QLEDs are enhanced simultaneously.Moreover,this work provides a generic strategy for the fabrication of fast-response and high-efficiency full-color QLEDs without luminescence delay,which plays a critical role in the practical industrialization of QLEDs.
基金financially supported by the National Natural Science Foundation of China(62075043)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZZ126).
文摘Interactive display devices integrating multiple functions have become a development trend of display technology.The excellent luminescence properties of perovskite quantum dots(PQDs)make it an ideal luminescent material for the next generation of wide-color gamut displays.Here we design and fabricate dual-function light-sensing/displaying light-emitting devices based on PQDs.The devices can display information as an output port,and simultaneously sense outside light signals as an input port and modulate the display information in a non-contact mode.The dual functions were attributed to the device designs:(1)the hole transport layer in the devices also acts as the light-sensing layer to absorb outside light signals;(2)the introduced hole trapping layer interface can trap holes originating from the light-sensing layer,and thus tune the charge transport properties and the light-emitting intensities.The sensing and display behavior of the device can be further modulated by light signals with different time and space information.This fusion of sensing and display functions has broad prospects in non-contact interactive screens and communication ports.
