The energy dispersive relation of surface dangling bond state on InP(īīī)clear,surface has been measured bg the angle resolved photo-mission.The theoretical calculation based on a slab model and extended Hücke...The energy dispersive relation of surface dangling bond state on InP(īīī)clear,surface has been measured bg the angle resolved photo-mission.The theoretical calculation based on a slab model and extended Hückel theory agreed well with the experimental result if a surface relaxed atomic structure model for InP(īīī)(1x1)is postulated.展开更多
Transient photovoltage of ITO/organic/Al cells is studied under different bias polarities and voltages.It is found that for an ITO/NPB/Al cell,light incidence on the Al side induces more bias-dependent transient photo...Transient photovoltage of ITO/organic/Al cells is studied under different bias polarities and voltages.It is found that for an ITO/NPB/Al cell,light incidence on the Al side induces more bias-dependent transient photovoltage variation when the photovoltage is positive than when it is negative.However,for an ITO/C60 /Al cell,the variation characteristics of transient photovoltage is reversed.These results support the previously proposed mechanism that Al could inject charges into the organic layer upon photon excitation,indicating that the absorption of electrode can also contribute to photovoltaic effect.展开更多
The transient photovoltage of ITO/CuPc/AI is studied. The transient photovoltage under the Al side illumination is much greater than that under ITO side illumination. It is not negligible while light is almost complet...The transient photovoltage of ITO/CuPc/AI is studied. The transient photovoltage under the Al side illumination is much greater than that under ITO side illumination. It is not negligible while light is almost completely absorbed by the Al layer. It seems that the light absorption of the Al layer could enhance the generation of the photoinduced carriers in the organic layer, which is further shown by the transient photovoltage study of ITO/Al/NPB/Au. A possible mechanism proposed is that the holes generated in the Al are because of light absorption that is injected from the AI to organic materials. This results in further charge separation by the internal built-in electric field.展开更多
The exciton dissociation at ITO/pentacene interface is studied by means of transient photovoltage measurement.Opposite to ITO/NPB,ITO/CuPc or ITO/C60 interface where polarity change of transient photovoltage is observ...The exciton dissociation at ITO/pentacene interface is studied by means of transient photovoltage measurement.Opposite to ITO/NPB,ITO/CuPc or ITO/C60 interface where polarity change of transient photovoltage is observed,no interfacial dissociation is found at room temperature,which indicates a lack of Frenkel excitons in pentacene.Temperature-dependent photoluminescence (PL) is investigated.More like the behavior of inorganic semiconductors,the integrated PL intensity exhibits monotonic decrease with increasing temperature.A nonradiative path with characteristic activation energy of 8 meV is found to dominate at room temperature.The PL measurement also indicates that like in inorganic semiconductors,other types of excitation,for example,free carriers,could be responsible for the photoelectric processes.展开更多
We present in this paper a new method,based on measurements of conventional direct current-voltage(I-V) characteristics and transient voltage-time(V-t) characteristics during the discharge process,for determining capa...We present in this paper a new method,based on measurements of conventional direct current-voltage(I-V) characteristics and transient voltage-time(V-t) characteristics during the discharge process,for determining capacitance-voltage(C-V) characteris-tics of organic semiconductor devices.Derivatives of I-V and V-t,dI/dV and dV/dt,are related with C by a simple formula C=-V(dI/dV)/(dV/dt)The validity of the method is confirmed by experimental data measured from a set of single-organic-layer devices with different layer thicknesses.展开更多
文摘The energy dispersive relation of surface dangling bond state on InP(īīī)clear,surface has been measured bg the angle resolved photo-mission.The theoretical calculation based on a slab model and extended Hückel theory agreed well with the experimental result if a surface relaxed atomic structure model for InP(īīī)(1x1)is postulated.
基金supported by the Ministry of Science and Technology of Chinathe National Natural Science Foundation of ChinaShanghai Science and Technology Committee
文摘Transient photovoltage of ITO/organic/Al cells is studied under different bias polarities and voltages.It is found that for an ITO/NPB/Al cell,light incidence on the Al side induces more bias-dependent transient photovoltage variation when the photovoltage is positive than when it is negative.However,for an ITO/C60 /Al cell,the variation characteristics of transient photovoltage is reversed.These results support the previously proposed mechanism that Al could inject charges into the organic layer upon photon excitation,indicating that the absorption of electrode can also contribute to photovoltaic effect.
基金supported by the Ministry of Science and Technology of China (Grant No. 2012CB921401)the National Natural Science Foundation of China (Grant No. 11134002)
文摘The transient photovoltage of ITO/CuPc/AI is studied. The transient photovoltage under the Al side illumination is much greater than that under ITO side illumination. It is not negligible while light is almost completely absorbed by the Al layer. It seems that the light absorption of the Al layer could enhance the generation of the photoinduced carriers in the organic layer, which is further shown by the transient photovoltage study of ITO/Al/NPB/Au. A possible mechanism proposed is that the holes generated in the Al are because of light absorption that is injected from the AI to organic materials. This results in further charge separation by the internal built-in electric field.
基金supported by the Ministry of Science and Technology of China (Grant No.2009CB929200)the National Natural Science Foundation of China (Grant No.10621063)the Science and Technology Commission of Shanghai Municipality (Grant No.08JC1402300)
文摘The exciton dissociation at ITO/pentacene interface is studied by means of transient photovoltage measurement.Opposite to ITO/NPB,ITO/CuPc or ITO/C60 interface where polarity change of transient photovoltage is observed,no interfacial dissociation is found at room temperature,which indicates a lack of Frenkel excitons in pentacene.Temperature-dependent photoluminescence (PL) is investigated.More like the behavior of inorganic semiconductors,the integrated PL intensity exhibits monotonic decrease with increasing temperature.A nonradiative path with characteristic activation energy of 8 meV is found to dominate at room temperature.The PL measurement also indicates that like in inorganic semiconductors,other types of excitation,for example,free carriers,could be responsible for the photoelectric processes.
基金supported by the Shanghai Committee of Science and Technology, China (Grant No. 08Jc1402300)
文摘We present in this paper a new method,based on measurements of conventional direct current-voltage(I-V) characteristics and transient voltage-time(V-t) characteristics during the discharge process,for determining capacitance-voltage(C-V) characteris-tics of organic semiconductor devices.Derivatives of I-V and V-t,dI/dV and dV/dt,are related with C by a simple formula C=-V(dI/dV)/(dV/dt)The validity of the method is confirmed by experimental data measured from a set of single-organic-layer devices with different layer thicknesses.
