Bottom surface of active layers and interface of indium tin oxide(ITO)electrodes and active layers play a crucial role in determining the performance of polymer photodetectors with photomultiplication(PM-PPDs).The int...Bottom surface of active layers and interface of indium tin oxide(ITO)electrodes and active layers play a crucial role in determining the performance of polymer photodetectors with photomultiplication(PM-PPDs).The interfacial trapped electron distribution closing to ITO electrodes will determine spectral response range and external quantum efficiency(EQE)of PMPPDs.The bottom interface is more sensitive than top interface when light is coming from the ITO side,and the larger density of generated charge on the bottom interfaces will induce interfacial band more bending for efficient charge tunneling injection.Highly sensitive and sub-microsecond PM-PPDs are achieved with PMBBDT:Y6(100:7,w/w)as active layers under forward bias,yielding EQE of 18,700%at 320 nm,21,700%at 600 nm and 16,400%at 810 nm under a bias of 7 V,respectively,as well as fast response time of 79μs.The high EQE of the PM-PPDs is attributed to efficient hole tunneling injection from ITO electrode under forward bias.The electron traps closing to ITO electrode will be quickly filled up when light is coming from ITO side,leading to interfacial band more bending for hole tunneling injection.Importantly,the PM-PPDs is performed to measure heart rate(HR)and blood oxygen saturation(SpO_(2)),and the measured data by the PM-PPDs are very similar with those obtained by commercial photodetectors.展开更多
Photomultiplication-type polymer photodetectors(PM-PPDs)were achieved with polymer P3HT as donor and PY3Se-1V as acceptor based on structure of ITO/PEDOT:PSS/active layer/Al.The optimal weight ratio of P3HT to PY3Se-1...Photomultiplication-type polymer photodetectors(PM-PPDs)were achieved with polymer P3HT as donor and PY3Se-1V as acceptor based on structure of ITO/PEDOT:PSS/active layer/Al.The optimal weight ratio of P3HT to PY3Se-1V is about 100:3.Amounts of isolated electron traps are formed with PY3Se-1V surrounded by P3HT due to rather less content of PY3Se-1V in active layers and about 0.94 e V energy offset between the lowest unoccupied molecular orbitals(LUMO)of P3HT and PY3Se-1V.The optimal PM-PPDs exhibit broad spectral response from 350 to 950 nm and external quantum efficiency(EQE)values of68,200%at 360 nm,26,400%at 630 nm and 19,500%at 850 nm under-15 V bias.The working mechanism of PM-PPDs is attributed to the interfacial trap-assisted hole tunneling injection from external circuit.The performance of PM-PPDs can be further improved by incorporating appropriate PMBBDT with high hole mobility as the third component.The EQE values of optimal ternary PM-PPDs are increased to 105,000%at 360 nm,40,000%at 630 nm and 31,800%at 850 nm under-15 V bias,benefiting from the enhanced hole transport in ternary active layers.The optimal ternary PM-PPDs were successfully applied in a light-controlled circuit to turn on or turn off light emitting diode(LED).展开更多
基金This work was supported by the National Natural Science Foundation of China(61975006,62075155,61875072)Beijing Natural Science Foundation(4192049).
文摘Bottom surface of active layers and interface of indium tin oxide(ITO)electrodes and active layers play a crucial role in determining the performance of polymer photodetectors with photomultiplication(PM-PPDs).The interfacial trapped electron distribution closing to ITO electrodes will determine spectral response range and external quantum efficiency(EQE)of PMPPDs.The bottom interface is more sensitive than top interface when light is coming from the ITO side,and the larger density of generated charge on the bottom interfaces will induce interfacial band more bending for efficient charge tunneling injection.Highly sensitive and sub-microsecond PM-PPDs are achieved with PMBBDT:Y6(100:7,w/w)as active layers under forward bias,yielding EQE of 18,700%at 320 nm,21,700%at 600 nm and 16,400%at 810 nm under a bias of 7 V,respectively,as well as fast response time of 79μs.The high EQE of the PM-PPDs is attributed to efficient hole tunneling injection from ITO electrode under forward bias.The electron traps closing to ITO electrode will be quickly filled up when light is coming from ITO side,leading to interfacial band more bending for hole tunneling injection.Importantly,the PM-PPDs is performed to measure heart rate(HR)and blood oxygen saturation(SpO_(2)),and the measured data by the PM-PPDs are very similar with those obtained by commercial photodetectors.
基金supported by the Fundamental Research Funds for the Central Universities(2021YJS176)the National Natural Science Foundation of China(61975006,62075155,62175011)+1 种基金the Postdoctoral Innovative Talent Support Program(BX20200042)the China Postdoctoral Science Foundation(2020M680327)。
文摘Photomultiplication-type polymer photodetectors(PM-PPDs)were achieved with polymer P3HT as donor and PY3Se-1V as acceptor based on structure of ITO/PEDOT:PSS/active layer/Al.The optimal weight ratio of P3HT to PY3Se-1V is about 100:3.Amounts of isolated electron traps are formed with PY3Se-1V surrounded by P3HT due to rather less content of PY3Se-1V in active layers and about 0.94 e V energy offset between the lowest unoccupied molecular orbitals(LUMO)of P3HT and PY3Se-1V.The optimal PM-PPDs exhibit broad spectral response from 350 to 950 nm and external quantum efficiency(EQE)values of68,200%at 360 nm,26,400%at 630 nm and 19,500%at 850 nm under-15 V bias.The working mechanism of PM-PPDs is attributed to the interfacial trap-assisted hole tunneling injection from external circuit.The performance of PM-PPDs can be further improved by incorporating appropriate PMBBDT with high hole mobility as the third component.The EQE values of optimal ternary PM-PPDs are increased to 105,000%at 360 nm,40,000%at 630 nm and 31,800%at 850 nm under-15 V bias,benefiting from the enhanced hole transport in ternary active layers.The optimal ternary PM-PPDs were successfully applied in a light-controlled circuit to turn on or turn off light emitting diode(LED).
