北京大学supermicro

Time:4:00pm,Nov.
8,2017(Wednesday)时间:2017年11月8日(周三)下午4:00Venue:RoomW563,Physicsbuilding,PekingUniversity地点:北京大学物理楼,西563会议室北京大学量子材料科学中心InternationalCenterforQuantumMaterials,PKUWeeklySeminarAbstract:http://icqm.
pku.
edu.
cn/JunHeSchoolofPhysicsandElectronics,CentralSouthUniversityUltrafastNonlinearOpticalEffectsinBlackPhosphorusNanomaterialsHost:孙栋sundong@pku.
edu.
cnAsanewmemberoftwo-dimensionalmaterials,blackphosphorus(BP)hasattractedunprecedentedattentionowingtoitsuniqueelectronicandoptoelectronicproperties.
Inthiswork,afacileliquidexfoliationmethodwasusedtoprepareBPnanosheetsandBPQuantumDots(QDs)suspendedinNMPsolvent.
TheZ-scanandpump-probemeasurementsindicatedthatBPnanosheetsandQDsexhibittypicalbroadbandsaturableabsorptionproperties.
ForBPnanosheets,anultrafastrecoverytime(~50fs)andslowelectron-holerecombinationtime(~1.
9ps)ofBPnanosheetsweredeterminedat1550nmandcorrelatedwithintrabandrelaxationandinterbandcarrierrecombination,respectively.
ForBPQDs,theultravioletintrabandrelaxationtimemaybetooshorttoberesolved,whiletheextractedinterbandrelaxationtimewas200~300fs.
Thecarrierdiffusionlengthof5nmwasobtainedbasedonnon-equilibriumcarriersdiffusiontheory,whichisconsistentwiththesizeofBPQDs.
TheexcellentnonlinearopticalcharacteristicsofBPnanosheetsandQDsmayleadtonewapplicationsinlasersandopticalswitching.
AboutthespeakerDr.
JunHeisaProfessorinSchoolofPhysicsandElectronicsatCentralSouthUniversity,China.
HeobtainedhisB.
S.
andM.
S.
degreesinphysicsfromJilinUniversity,China.
HeundertookhisPh.
D.
studiesattheNationalUniversityofSingapore,Singapore,andjoinedthesameuniversityasaResearchFellow.
From2006to2009,hepursuedfurtherpostdoctoralworkattheCityCollegeoftheCityUniversityofNewYork,USA,andattheUniversityofToronto,Canada.
Since2014,hehasheldtheChairinSchoolofPhysicsandElectronicsatCentralSouthUniversity,China.
HealsoservedasDeputyDirectoratHunanKeyLaboratoryofSuper-MicrostructureandUltrafastProcess,China.
HeissupportedbyNationalScienceFundationforExcellentYoungScientistsandProgramforNewCenturyExcellentTalents,China.
Hehasauthoredandco-authoredover90journalpapersandholdseveralpatents.
Hiscurrentresearchinterestsincludeultrafastnonlinearoptics,spintronics,andtwo-dimensionalmaterials.