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NANOEXPRESSOpenAccessStructuralandopticalcharacterizationsofInPBithinfilmsgrownbymolecularbeamepitaxyYiGu1,KaiWang1,HaifeiZhou1,YaoyaoLi1,ChunfangCao1,LiyaoZhang1,YonggangZhang1,QianGong1*andShuminWang1,2*AbstractInPBithinfilmshavebeengrownonInPbygassourcemolecularbeamepitaxy.
AmaximumBicompositionof2.
4%isdeterminedbyRutherfordbackscatteringspectrometry.
X-raydiffractionmeasurementsshowgoodstructuralqualityforBicompositionupto1.
4%andapartiallyrelaxedstructureforhigherBicontents.
Thebandgapwasmeasuredbyopticalabsorption,andthebandgapreductioncausedbytheBiincorporationwasestimatedtobeabout56meV/Bi%.
StrongandbroadphotoluminescencesignalswereobservedatroomtemperatureforsampleswithxBi180Kthepeakataround0.
95eVdisappearsandtheothertwopeaksareoverlapped.
Thepeakenergieslabeledpeaks1and2redshiftedabout82and108meV,respectively,whenthetemperatureincreasesfrom8to300K,compar-abletothered-shiftedvalueof71meVfortheInPrefer-encesample.
However,thepeakenergieslabeledpeak3arealmostconstantataround0.
95eVatvarioustempera-tures.
Toourknowledge,thePLsignalofdilutebismidesfarfromtheband-to-bandtransitionwasscarcelyreportedFigure3BandgapenergyofInPBimeasuredfromabsorptionspectraasafunctionofBicomposition.
Theerrorbarsoftheexperimentaldataarelabeled.
Thesolidlineisthefittinglineoftheexperimentaldata.
Figure4PLspectraofInPBifilmswithvariousBicompositionsatRT.
ThePLspectrumofInPreferencesampleisalsoshown.
Guetal.
NanoscaleResearchLetters2014,9:24Page3of5http://www.
nanoscalereslett.
com/content/9/1/24inthepast.
Markoetal.
observedtheclearandbroadPLsignalofInGaAsBisamplefrom0.
46eV(2.
7μm)to0.
65eV(1.
8μm)withamuchlongerwavelengththantheband-to-bandPLat0.
786eV(1.
6μm)andattributedtothecompositionalinhomogeneity[19].
Theysuggestedthatthelocalizednarrower-gapregionstrappedcarriersatlowtemperaturesandproducedthelongwavelengthemis-sion.
However,theycouldonlyobservethelongwave-lengthPLatT<160K,andthePLintensitydroppedrapidlywithtemperature,whichcontraststoourresults.
Inaddition,transmissionelectronmicroscopeandsecond-aryionmassspectrometrymeasurements(notshownhere)haverevealedquiteuniformBicontentsinourInPBisamples.
AnotherpossibleexplanationisthatthelongwavelengthPLisfromtherecombinationrelatedtodeepenergylevels.
TheBiincorporationatlowgrowthtemper-aturesmayintroduceBi-relateddefectssuchasBi-antisites[20],whichcouldactasadeeprecombinationcenter.
Notethattheband-to-bandPLofInPBiwasnotobservedevenat8Kinourexperiments.
Thissuggestsaveryshortcarrierlifetimeatthebandgapandalongcar-rierlifetimeatthedeeplevels.
Therefore,theoriginofthePLsignalsisstillunclearatpresent,andfurtherinvestiga-tionsareneededtofullyaccountforthisphenomenon.
ConclusionsThestructuralandopticalpropertiesof430-nm-thickInPBithinfilmshavebeeninvestigated.
TheBicomposi-tionsdeterminedbyRBSmeasurementswereintherangeof0.
6%to2.
4%.
AgoodqualityhasbeendemonstratedforthesampleswiththeBicompositionlowerthan1.
4%,whereasthesampleswithhigherBicontentsbecomepar-tiallyrelaxed.
ItwasfoundthattheincorporationofBicausedthebandgapreductionofabout56meV/Bi%.
StrongandbroadPLsignalscontainingmultipleover-lappedpeakswereobservedatroomtemperaturewithpeakwavelengththatvariedfrom1.
4to1.
9μm,whichisfarfromtheband-to-bandtransition.
TheoriginsofthelongwavelengthPLsignalswerediscussed,butfurtherin-vestigationisnecessaryforunambiguousexplanation.
CompetinginterestsTheauthorsdeclarethattheyhavenocompetinginterests.
Authors'contributionsYGcarriedouttheopticalmeasurements,analyzedtheresults,andwrotethemanuscript.
KWgrewthesamplesandperformedXRDmeasurements.
HFZ,YYL,CFC,andLYZhelpedinthemeasurementsandanalysisofresults.
YGZsupervisedthePLexperimentsandrevisedthemanuscript.
QGsupervisedthegrowthandjoinedthediscussions.
SMWproposedtheinitialwork,supervisedthesampledesignandanalysis,andrevisedthemanuscript.
Allauthorsreadandapprovedthefinalmanuscript.
AcknowledgementsTheauthorswishtoacknowledgethesupportofNationalBasicResearchProgramofChinaundergrantnos.
2014CB643900and2012CB619202;theNationalNaturalScienceFoundationofChinaundergrantnos.
61334004,61204133,and61275113;theGuidingProjectofChineseAcademyofSciencesundergrantno.
XDA5-1;theKeyResearchProgramoftheChineseAcademyofSciencesundergrantno.
KGZD-EW-804;andtheInnovationResearchGroupProjectofNationalNaturalScienceFoundationundergrantno.
61321492.
Received:13November2013Accepted:18December2013Published:13January2014Figure5PLspectraoftheInPBisamplewith1.
0%Biatvarioustemperatures.
Theoverlappedmulti-peaksobtainedbyusingGaussianfittingareshownasthedashedanddottedlinesforthecasesof8and300K,andthemulti-peaksofPLspectraatothertemperatureswerealsoobtainedsimilarly.
Figure6PLenergiesofthemulti-peaksatvarioustemperaturesfortheInPBisamplewith1.
0%Bi.
Theenergyvalueswereextractedbyusingthemulti-peakGaussianfittingofthePLspectraatvarioustemperatures.
Guetal.
NanoscaleResearchLetters2014,9:24Page4of5http://www.
nanoscalereslett.
com/content/9/1/24References1.
FrancoeurS,SeongMJ,MascarenhasA,TixierS,AdamcykM,TiedjeT:BandgapofGaAs1xBix,06%.
ApplPhysLett2003,82:3874–3876.
2.
AlberiK,WuJ,WalukiewiczW,YuK,DubonO,WatkinsS,WangC,LiuX,ChoYJ,FurdynaJ:Valence-bandanticrossinginmismatchedIII-Vsemiconductoralloys.
PhysRevB2007,75:045203.
3.
SweeneySJ,JinSR:Bismide-nitridealloys:promisingforefficientlightemittingdevicesinthenear-andmid-infrared.
JApplPhys2013,113:043110.
4.
HossainN,MarkoIP,JinSR,HildK,SweeneySJ,LewisRB,BeatonDA,TiedjeT:RecombinationmechanismsandbandalignmentofGaAs1xBix/GaAslightemittingdiodes.
ApplPhysLett2012,100:051105.
5.
TominagaY,OeK,YoshimotoM:LowtemperaturedependenceofoscillationwavelengthinGaAs1-xBixlaserbyphoto-pumping.
ApplPhysExpress2010,3:62201.
6.
LudewigP,KnaubN,HossainN,ReinhardS,NattermannL,MarkoIP,JinSR,HildK,ChatterjeeS,StolzW,SweeneySJ,VolzK:ElectricalinjectionGa(AsBi)/(AlGa)Assinglequantumwelllaser.
ApplPhysLett2013,102:242115.
7.
StreubelK,LinderN,WirthR,JaegerA:HighbrightnessAlGaInPlight-emittingdiodes.
IEEEJSelTopicsinQuanElectron2002,8:321–332.
8.
YamamotoM,YamamotoN,NakanoJ:MOVPEgrowthofstrainedInAsP/InGaAsPquantum-wellstructuresforlow-threshold1.
3-μmlasers.
IEEEJQuanElectron1994,30:554–561.
9.
BerdingMA,SherA,ChenAB,MillerWE:Structuralpropertiesofbismuth-bearingsemiconductoralloys.
JApplPhys1988,63:107–115.
10.
DeanPJ,WhiteAM,WilliamsEW,AstlesMG:Theisoelectronictrapbismuthinindiumphosphide.
SolidStateCommun1971,9:1555–1558.
11.
RuhleW,SchmidW,MeckR,StathN,FischbachJU,StrottnerI,BenzKW,PilkuhnM:Isoelectronicimpuritystatesindirect-gapIII-Vcompounds:thecaseofInP:Bi.
PhysRevB1978,18:7022–7032.
12.
ZhangYG,GuY,WangK,FangX,LiAZ,LiuKH:Fouriertransforminfraredspectroscopyapproachformeasurementsofphotoluminescenceandelectroluminescenceinmid-infrared.
RevSciInstrum2012,83:053106.
13.
FengG,YoshimotoM,OeK,ChayaharaA,HorinoY:NewIII-VsemiconductorInGaAsBialloygrownbymolecularbeamepitaxy.
JpnJApplPhys2005,44:L1161.
14.
JanottiA,WeiSH,ZhangSB:TheoreticalstudyoftheeffectsofisovalentcoalloyingofBiandNinGaAs.
PhysRevB2002,65:115203.
15.
MaKY,FangZM,CohenRM,StringfellowGB:Organometallicvapor-phaseepitaxygrowthandcharacterizationofBi-containingIII/Valloys.
JApplPhys1990,68:4586.
16.
BiWG,TuCW:NincorporationinInPandbandgapbowingofInNxP1-x.
JApplPhys1996,80:1934–1936.
17.
BarnettSA:DirectE0energygapsofbismuth-containingIII-Valloyspre-dictedusingquantumdielectrictheory.
JVacuumSci&TechnolA:Vacuum,Surfaces&Films1987,5:2845.
18.
AlberiK,DubonOD,WalukiewiczW,YuKM,BertulisK,KrotkusA:ValencebandanticrossinginGaBixAs1x.
ApplPhysLett2007,91:051909.
19.
MarkoIP,BatoolZ,HildK,JinSR,HossainN,HoseaTJC,PetropoulosJP,ZhongY,DongmoPB,ZideJMO,SweeneySJ:TemperatureandBi-concentrationdependenceofthebandgapandspin-orbitsplittinginInGaBiAs/InPsemiconductorsformid-infraredapplications.
ApplPhysLett2012,101:221108.
20.
KunzerM,JostW,KaufmannU,HobgoodHM,ThomasRN:IdentificationoftheBiGaheteroantisitedefectinGaAs:Bi.
PhysRevB1993,48:4437–4441.
doi:10.
1186/1556-276X-9-24Citethisarticleas:Guetal.
:StructuralandopticalcharacterizationsofInPBithinfilmsgrownbymolecularbeamepitaxy.
NanoscaleResearchLetters20149:24.
Submityourmanuscripttoajournalandbenetfrom:7Convenientonlinesubmission7Rigorouspeerreview7Immediatepublicationonacceptance7Openaccess:articlesfreelyavailableonline7Highvisibilitywithintheeld7RetainingthecopyrighttoyourarticleSubmityournextmanuscriptat7springeropen.
comGuetal.
NanoscaleResearchLetters2014,9:24Page5of5http://www.
nanoscalereslett.
com/content/9/1/24
AmaximumBicompositionof2.
4%isdeterminedbyRutherfordbackscatteringspectrometry.
X-raydiffractionmeasurementsshowgoodstructuralqualityforBicompositionupto1.
4%andapartiallyrelaxedstructureforhigherBicontents.
Thebandgapwasmeasuredbyopticalabsorption,andthebandgapreductioncausedbytheBiincorporationwasestimatedtobeabout56meV/Bi%.
StrongandbroadphotoluminescencesignalswereobservedatroomtemperatureforsampleswithxBi180Kthepeakataround0.
95eVdisappearsandtheothertwopeaksareoverlapped.
Thepeakenergieslabeledpeaks1and2redshiftedabout82and108meV,respectively,whenthetemperatureincreasesfrom8to300K,compar-abletothered-shiftedvalueof71meVfortheInPrefer-encesample.
However,thepeakenergieslabeledpeak3arealmostconstantataround0.
95eVatvarioustempera-tures.
Toourknowledge,thePLsignalofdilutebismidesfarfromtheband-to-bandtransitionwasscarcelyreportedFigure3BandgapenergyofInPBimeasuredfromabsorptionspectraasafunctionofBicomposition.
Theerrorbarsoftheexperimentaldataarelabeled.
Thesolidlineisthefittinglineoftheexperimentaldata.
Figure4PLspectraofInPBifilmswithvariousBicompositionsatRT.
ThePLspectrumofInPreferencesampleisalsoshown.
Guetal.
NanoscaleResearchLetters2014,9:24Page3of5http://www.
nanoscalereslett.
com/content/9/1/24inthepast.
Markoetal.
observedtheclearandbroadPLsignalofInGaAsBisamplefrom0.
46eV(2.
7μm)to0.
65eV(1.
8μm)withamuchlongerwavelengththantheband-to-bandPLat0.
786eV(1.
6μm)andattributedtothecompositionalinhomogeneity[19].
Theysuggestedthatthelocalizednarrower-gapregionstrappedcarriersatlowtemperaturesandproducedthelongwavelengthemis-sion.
However,theycouldonlyobservethelongwave-lengthPLatT<160K,andthePLintensitydroppedrapidlywithtemperature,whichcontraststoourresults.
Inaddition,transmissionelectronmicroscopeandsecond-aryionmassspectrometrymeasurements(notshownhere)haverevealedquiteuniformBicontentsinourInPBisamples.
AnotherpossibleexplanationisthatthelongwavelengthPLisfromtherecombinationrelatedtodeepenergylevels.
TheBiincorporationatlowgrowthtemper-aturesmayintroduceBi-relateddefectssuchasBi-antisites[20],whichcouldactasadeeprecombinationcenter.
Notethattheband-to-bandPLofInPBiwasnotobservedevenat8Kinourexperiments.
Thissuggestsaveryshortcarrierlifetimeatthebandgapandalongcar-rierlifetimeatthedeeplevels.
Therefore,theoriginofthePLsignalsisstillunclearatpresent,andfurtherinvestiga-tionsareneededtofullyaccountforthisphenomenon.
ConclusionsThestructuralandopticalpropertiesof430-nm-thickInPBithinfilmshavebeeninvestigated.
TheBicomposi-tionsdeterminedbyRBSmeasurementswereintherangeof0.
6%to2.
4%.
AgoodqualityhasbeendemonstratedforthesampleswiththeBicompositionlowerthan1.
4%,whereasthesampleswithhigherBicontentsbecomepar-tiallyrelaxed.
ItwasfoundthattheincorporationofBicausedthebandgapreductionofabout56meV/Bi%.
StrongandbroadPLsignalscontainingmultipleover-lappedpeakswereobservedatroomtemperaturewithpeakwavelengththatvariedfrom1.
4to1.
9μm,whichisfarfromtheband-to-bandtransition.
TheoriginsofthelongwavelengthPLsignalswerediscussed,butfurtherin-vestigationisnecessaryforunambiguousexplanation.
CompetinginterestsTheauthorsdeclarethattheyhavenocompetinginterests.
Authors'contributionsYGcarriedouttheopticalmeasurements,analyzedtheresults,andwrotethemanuscript.
KWgrewthesamplesandperformedXRDmeasurements.
HFZ,YYL,CFC,andLYZhelpedinthemeasurementsandanalysisofresults.
YGZsupervisedthePLexperimentsandrevisedthemanuscript.
QGsupervisedthegrowthandjoinedthediscussions.
SMWproposedtheinitialwork,supervisedthesampledesignandanalysis,andrevisedthemanuscript.
Allauthorsreadandapprovedthefinalmanuscript.
AcknowledgementsTheauthorswishtoacknowledgethesupportofNationalBasicResearchProgramofChinaundergrantnos.
2014CB643900and2012CB619202;theNationalNaturalScienceFoundationofChinaundergrantnos.
61334004,61204133,and61275113;theGuidingProjectofChineseAcademyofSciencesundergrantno.
XDA5-1;theKeyResearchProgramoftheChineseAcademyofSciencesundergrantno.
KGZD-EW-804;andtheInnovationResearchGroupProjectofNationalNaturalScienceFoundationundergrantno.
61321492.
Received:13November2013Accepted:18December2013Published:13January2014Figure5PLspectraoftheInPBisamplewith1.
0%Biatvarioustemperatures.
Theoverlappedmulti-peaksobtainedbyusingGaussianfittingareshownasthedashedanddottedlinesforthecasesof8and300K,andthemulti-peaksofPLspectraatothertemperatureswerealsoobtainedsimilarly.
Figure6PLenergiesofthemulti-peaksatvarioustemperaturesfortheInPBisamplewith1.
0%Bi.
Theenergyvalueswereextractedbyusingthemulti-peakGaussianfittingofthePLspectraatvarioustemperatures.
Guetal.
NanoscaleResearchLetters2014,9:24Page4of5http://www.
nanoscalereslett.
com/content/9/1/24References1.
FrancoeurS,SeongMJ,MascarenhasA,TixierS,AdamcykM,TiedjeT:BandgapofGaAs1xBix,0
ApplPhysLett2003,82:3874–3876.
2.
AlberiK,WuJ,WalukiewiczW,YuK,DubonO,WatkinsS,WangC,LiuX,ChoYJ,FurdynaJ:Valence-bandanticrossinginmismatchedIII-Vsemiconductoralloys.
PhysRevB2007,75:045203.
3.
SweeneySJ,JinSR:Bismide-nitridealloys:promisingforefficientlightemittingdevicesinthenear-andmid-infrared.
JApplPhys2013,113:043110.
4.
HossainN,MarkoIP,JinSR,HildK,SweeneySJ,LewisRB,BeatonDA,TiedjeT:RecombinationmechanismsandbandalignmentofGaAs1xBix/GaAslightemittingdiodes.
ApplPhysLett2012,100:051105.
5.
TominagaY,OeK,YoshimotoM:LowtemperaturedependenceofoscillationwavelengthinGaAs1-xBixlaserbyphoto-pumping.
ApplPhysExpress2010,3:62201.
6.
LudewigP,KnaubN,HossainN,ReinhardS,NattermannL,MarkoIP,JinSR,HildK,ChatterjeeS,StolzW,SweeneySJ,VolzK:ElectricalinjectionGa(AsBi)/(AlGa)Assinglequantumwelllaser.
ApplPhysLett2013,102:242115.
7.
StreubelK,LinderN,WirthR,JaegerA:HighbrightnessAlGaInPlight-emittingdiodes.
IEEEJSelTopicsinQuanElectron2002,8:321–332.
8.
YamamotoM,YamamotoN,NakanoJ:MOVPEgrowthofstrainedInAsP/InGaAsPquantum-wellstructuresforlow-threshold1.
3-μmlasers.
IEEEJQuanElectron1994,30:554–561.
9.
BerdingMA,SherA,ChenAB,MillerWE:Structuralpropertiesofbismuth-bearingsemiconductoralloys.
JApplPhys1988,63:107–115.
10.
DeanPJ,WhiteAM,WilliamsEW,AstlesMG:Theisoelectronictrapbismuthinindiumphosphide.
SolidStateCommun1971,9:1555–1558.
11.
RuhleW,SchmidW,MeckR,StathN,FischbachJU,StrottnerI,BenzKW,PilkuhnM:Isoelectronicimpuritystatesindirect-gapIII-Vcompounds:thecaseofInP:Bi.
PhysRevB1978,18:7022–7032.
12.
ZhangYG,GuY,WangK,FangX,LiAZ,LiuKH:Fouriertransforminfraredspectroscopyapproachformeasurementsofphotoluminescenceandelectroluminescenceinmid-infrared.
RevSciInstrum2012,83:053106.
13.
FengG,YoshimotoM,OeK,ChayaharaA,HorinoY:NewIII-VsemiconductorInGaAsBialloygrownbymolecularbeamepitaxy.
JpnJApplPhys2005,44:L1161.
14.
JanottiA,WeiSH,ZhangSB:TheoreticalstudyoftheeffectsofisovalentcoalloyingofBiandNinGaAs.
PhysRevB2002,65:115203.
15.
MaKY,FangZM,CohenRM,StringfellowGB:Organometallicvapor-phaseepitaxygrowthandcharacterizationofBi-containingIII/Valloys.
JApplPhys1990,68:4586.
16.
BiWG,TuCW:NincorporationinInPandbandgapbowingofInNxP1-x.
JApplPhys1996,80:1934–1936.
17.
BarnettSA:DirectE0energygapsofbismuth-containingIII-Valloyspre-dictedusingquantumdielectrictheory.
JVacuumSci&TechnolA:Vacuum,Surfaces&Films1987,5:2845.
18.
AlberiK,DubonOD,WalukiewiczW,YuKM,BertulisK,KrotkusA:ValencebandanticrossinginGaBixAs1x.
ApplPhysLett2007,91:051909.
19.
MarkoIP,BatoolZ,HildK,JinSR,HossainN,HoseaTJC,PetropoulosJP,ZhongY,DongmoPB,ZideJMO,SweeneySJ:TemperatureandBi-concentrationdependenceofthebandgapandspin-orbitsplittinginInGaBiAs/InPsemiconductorsformid-infraredapplications.
ApplPhysLett2012,101:221108.
20.
KunzerM,JostW,KaufmannU,HobgoodHM,ThomasRN:IdentificationoftheBiGaheteroantisitedefectinGaAs:Bi.
PhysRevB1993,48:4437–4441.
doi:10.
1186/1556-276X-9-24Citethisarticleas:Guetal.
:StructuralandopticalcharacterizationsofInPBithinfilmsgrownbymolecularbeamepitaxy.
NanoscaleResearchLetters20149:24.
Submityourmanuscripttoajournalandbenetfrom:7Convenientonlinesubmission7Rigorouspeerreview7Immediatepublicationonacceptance7Openaccess:articlesfreelyavailableonline7Highvisibilitywithintheeld7RetainingthecopyrighttoyourarticleSubmityournextmanuscriptat7springeropen.
comGuetal.
NanoscaleResearchLetters2014,9:24Page5of5http://www.
nanoscalereslett.
com/content/9/1/24
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