Limited charge carrier lifetime(τ)leads to the short charge carrier diffusion length(L_(D))and thus impedes the improvement of power conversion efficiencies(PCEs)of organic solar cells(OSCs).Herein,anthracene(AN)as t...Limited charge carrier lifetime(τ)leads to the short charge carrier diffusion length(L_(D))and thus impedes the improvement of power conversion efficiencies(PCEs)of organic solar cells(OSCs).Herein,anthracene(AN)as the additive is introduced into classical donor:acceptor pairs to increase theτ.Introducing AN efficiently enhances the crystallinity of the PM 6:BTP-eC 9+blend film to reduce the trap density and increase theτto 1.484μs,achieving the prolonged L_(D).The prolonged L_(D) enables the PM 6:BTP-eC 9+blend film to gain weaker charge carrier recombination,reduced leakage current,and shorter charge carrier extraction time in devices,compared with PM 6:BTP-eC 9 counterparts.Therefore,PM 6:BTP-eC 9+based OSCs achieve higher PCEs of 18.41%±0.16%than PM 6:BTP-eC 9 based ones(17.08%±0.11%).Moreover,the PM 6:L 8-BO+based OSC presents an impressive PCE of 19.14%.It demonstrates that introducing AN is an efficient method to increase theτfor prolonged L_(D),boosting PCEs of OSCs.展开更多
The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs b...The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs based on M-EMLs separated by polyethyleneimine ethoxylated(PEIE)layer with different stacking sequences of blue(B),green(G),and red(R)QDs layer were used to intuitively explore the injection,transportation and recombination processes of the charge carriers in QLEDs by using the time-resolved electroluminescence(TrEL)spectra.From the TrEL spectra mea-surements,green and red emissions were obtained first in the QLEDs with the EMLs sequences of G/PEIE/B/PEIE/R and B/PEIE/R/PEIE/G along the direction of light emission,respectively.While the QLEDs adopt EMLs sequences of B/PEIE/G/PEIE/R,the blue,green and red emissions were obtained nearly at the same time.The above phenomenon can be attributed to different charge carrier transmission and radiation recombination process in the EMLs due to different valence band offsets and conduction band offsets between R-,G-and B-QDs by using different sequences of EMLs.White emission with coordi-nates of(0.31,0.31)and correlated color temperature(CCT)of 5916 K was obtained in the QLEDs with the EMLs se-quences of B/PEIE/G/PEIE/R,which can be attributed to the relative uniform emission of B-,G-and R-QDs due to the effec-tive injection and radiation recombination of charge carriers in each of the EMLs.The above results have great significance for further understanding and improving the performance of QLEDs with M-EMLs.展开更多
基金Projects(52272056,52372056,52232003)supported by the National Natural Science Foundation of ChinaProject(2023RC3044)supported by the Science and Technology Innovation Program of Hunan Province,China。
文摘Limited charge carrier lifetime(τ)leads to the short charge carrier diffusion length(L_(D))and thus impedes the improvement of power conversion efficiencies(PCEs)of organic solar cells(OSCs).Herein,anthracene(AN)as the additive is introduced into classical donor:acceptor pairs to increase theτ.Introducing AN efficiently enhances the crystallinity of the PM 6:BTP-eC 9+blend film to reduce the trap density and increase theτto 1.484μs,achieving the prolonged L_(D).The prolonged L_(D) enables the PM 6:BTP-eC 9+blend film to gain weaker charge carrier recombination,reduced leakage current,and shorter charge carrier extraction time in devices,compared with PM 6:BTP-eC 9 counterparts.Therefore,PM 6:BTP-eC 9+based OSCs achieve higher PCEs of 18.41%±0.16%than PM 6:BTP-eC 9 based ones(17.08%±0.11%).Moreover,the PM 6:L 8-BO+based OSC presents an impressive PCE of 19.14%.It demonstrates that introducing AN is an efficient method to increase theτfor prolonged L_(D),boosting PCEs of OSCs.
文摘The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs based on M-EMLs separated by polyethyleneimine ethoxylated(PEIE)layer with different stacking sequences of blue(B),green(G),and red(R)QDs layer were used to intuitively explore the injection,transportation and recombination processes of the charge carriers in QLEDs by using the time-resolved electroluminescence(TrEL)spectra.From the TrEL spectra mea-surements,green and red emissions were obtained first in the QLEDs with the EMLs sequences of G/PEIE/B/PEIE/R and B/PEIE/R/PEIE/G along the direction of light emission,respectively.While the QLEDs adopt EMLs sequences of B/PEIE/G/PEIE/R,the blue,green and red emissions were obtained nearly at the same time.The above phenomenon can be attributed to different charge carrier transmission and radiation recombination process in the EMLs due to different valence band offsets and conduction band offsets between R-,G-and B-QDs by using different sequences of EMLs.White emission with coordi-nates of(0.31,0.31)and correlated color temperature(CCT)of 5916 K was obtained in the QLEDs with the EMLs se-quences of B/PEIE/G/PEIE/R,which can be attributed to the relative uniform emission of B-,G-and R-QDs due to the effec-tive injection and radiation recombination of charge carriers in each of the EMLs.The above results have great significance for further understanding and improving the performance of QLEDs with M-EMLs.
