摘要
Simultaneous and distinguishable detection of external stimuli such as light and temperature is of great interest for a variety of scientific and industrial applications.Theoretically,an organic semiconductor with low exciton binding energy,low thermal activation energy and good charge transporting property produces thermally enhanced photo-electric response in organic phototransistors(OPTs),which thus provides an ideal and effective way to realize the simultaneous and distinguishable detection of temperature and light.However,there is no report on such a kind of organic semiconductor until now.Herein,we designed and synthesized a narrow band gap organic small molecule semiconductor 2,5-bis(2-butyloctyl)-3,6-bis(5-(4-(diphenylamino)phenyl)thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione(DPP-T-TPA)with low exciton binding energy(about 37 meV)and small activation energy(about 61 meV)for distinct thermal-dependence of charge carrier and exciton.The low exciton binding energy enables the semiconductor to exhibit strong thermal dependence of exciton dissociation,which contributes to the thermally-enhanced photo-electric response.Furthermore,the low thermal activation energy produces the weak thermal dependence of charge transport,which avoids the disturbance of thermally-modulated charge transport on photo-electric response.Benefiting from these two features,phototransistors based on DPP-T-TPA show great potential in simultaneous and distinguishable detection of light and temperature,which represents a novel and efficient way for bifunctional detection.
基金
supported by the National Key Research and Development Program(2018YFA0703200,2016YFB0401100,2016YFA0200803)
National Natural Science Foundation of China(52073210,21905199,21573277,51633006)
Tianjin Natural Science Foundation(19JCZDJC37400,194214030036,20JCQNJC01520)。