Isixhobo sokubona i-avalanche esinemilinganiselo emibini ye-bipolar

I-Bipolar-two-dimensionalisixhobo sokubona ifoto se-avalanche

Isixhobo sokubona i-avalanche esinemilinganiselo emibini esibizwa ngokuba yi-bipolar (Isixhobo sokubona ifoto se-APD) ifezekisa ingxolo ephantsi kakhulu kunye nokufunyanwa kovakalelo oluphezulu

Ukufunyanwa kwee-photon ezimbalwa ngobuchule obuphezulu okanye ii-photon enye kunezinto ezibalulekileyo ezinokwenzeka kwiindawo ezifana nemifanekiso yokukhanya okubuthathaka, ukubona kude kunye ne-telemetry, kunye nonxibelelwano lwe-quantum. Phakathi kwazo, i-avalanche photodetector (APD) ibe yindlela ebalulekileyo kwicandelo lophando lwezixhobo ze-optoelectronic ngenxa yeempawu zayo zobukhulu obuncinci, ukusebenza kakuhle kunye nokudibanisa okulula. Umlinganiselo wesignali-kwingxolo (SNR) luphawu olubalulekileyo lwe-APD photodetector, efuna i-gain ephezulu kunye nomsinga omnyama ophantsi. Uphando malunga ne-van der Waals heterojunctions yezinto ezinemilinganiselo emibini (2D) lubonisa amathuba abanzi ekuphuhlisweni kwee-APD ezisebenzayo kakhulu. Abaphandi baseTshayina bakhethe izinto ze-semiconductor ezinemilinganiselo emibini ze-bipolar WSe₂ njengezinto ezibonisa ukukhanya kwaye balungiselela i-photodetector ye-APD ngononophelo enesakhiwo se-Pt/WSe₂/Ni esinomsebenzi ofanelekileyo wokusebenza, ukuze kusonjululwe ingxaki yengxolo ye-gain ye-APD photodetector yendabuko.

Iqela lophando licebise i-avalanche photodetector esekwe kwisakhiwo se-Pt/WSe₂/Ni, efikelele ekufumaneni imiqondiso yokukhanya ebuthathaka kakhulu kwinqanaba le-fW kubushushu begumbi. Bakhethe izinto ze-semiconductor ezinemilinganiselo emibini i-WSe₂, ezineempawu zombane ezibalaseleyo, kwaye badibanisa izixhobo ze-electrode ze-Pt kunye ne-Ni ukuze baphuhlise ngempumelelo uhlobo olutsha lwe-avalanche photodetector. Ngokwenza ngcono ngokuchanekileyo ukufana komsebenzi phakathi kwe-Pt, i-WSe₂ kunye ne-Ni, kwayilwa indlela yokuthutha enokuthintela ngempumelelo abathwali abamnyama ngelixa ivumela ngokukhethekileyo abathwali abaveliswe yifoto ukuba badlule. Le ndlela yokuthutha inciphisa kakhulu ingxolo egqithisileyo ebangelwa yi-ionization yempembelelo yomthwali, ivumela i-photodetector ukuba ifumane ukufunyanwa kwesignali ye-optical enobuthathaka kakhulu kwinqanaba lengxolo ephantsi kakhulu.

Emva koko, ukuze kucaciswe indlela esebenza ngayo i-avalanche ebangelwa yintsimi yombane ebuthathaka, abaphandi baqale bavavanya ukuhambelana kwemisebenzi yokusebenza yendalo yeentsimbi ezahlukeneyo ne-WSe₂. Uthotho lwezixhobo ze-metal-semiconductor-metal (MSM) ezinee-electrode zesinyithi ezahlukeneyo zenziwe kwaye kwenziwa uvavanyo olufanelekileyo kuzo. Ukongeza, ngokunciphisa ukusasazeka kwe-carrier ngaphambi kokuba i-avalanche iqale, ukungacwangciswa kwe-impact ionization kunokunciphisa, ngaloo ndlela kuncitshiswe ingxolo. Ke ngoko, kwenziwe uvavanyo olufanelekileyo. Ukubonisa ngakumbi ukongama kwe-Pt/WSe₂/Ni APD ngokweempawu zempendulo yexesha, abaphandi bavavanya ngakumbi i-bandwidth ye--3 dB yesixhobo phantsi kwamaxabiso ahlukeneyo okufumana i-photoelectric.

Iziphumo zovavanyo zibonisa ukuba i-Pt/WSe₂/Ni detector ibonisa amandla alinganayo nengxolo ephantsi kakhulu (NEP) kubushushu begumbi, eyi-8.07 fW/√Hz kuphela. Oku kuthetha ukuba i-detector inokuchonga imiqondiso ye-optical ebuthathaka kakhulu. Ukongeza, esi sixhobo sinokusebenza ngokuzinzileyo kwi-modulation frequency ye-20 kHz kunye ne-gain ephezulu ye-5×10⁵, sisombulula ngempumelelo imiqobo yobuchwephesha be-photovoltaic detectors zemveli ezinzima ukulinganisela i-gain ephezulu kunye ne-bandwidth. Olu phawu kulindeleke ukuba lubonelele ngeenzuzo ezibalulekileyo kwizicelo ezifuna i-gain ephezulu kunye nengxolo ephantsi.

Olu phando lubonisa indima ebalulekileyo yobunjineli bezinto kunye nokwenza ngcono ujongano lwe-interface ekuphuculeni ukusebenza kweii-photodetectorsNgokusebenzisa uyilo olunobuchule lwee-electrode kunye nezinto ezinemilinganiselo emibini, isiphumo sokukhusela abathwali abamnyama siye safezekiswa, nto leyo eye yanciphisa kakhulu ukuphazamiseka kwengxolo kwaye yaphucula ngakumbi ukusebenza kakuhle kokufumanisa.

Ukusebenza kwale detector akubonakali nje kuphela kwiimpawu ze-photoelectric, kodwa kukwanamathuba amaninzi okusetyenziswa. Ngenxa yokuthintela kwayo ngempumelelo umbane omnyama kubushushu begumbi kunye nokufunxwa ngokufanelekileyo kwezixhobo eziveliswa yi-photo, le detector ifanelekile ngokukodwa ekufumaneni imiqondiso yokukhanya ebuthathaka kwiindawo ezifana nokubeka esweni okusingqongileyo, ukujonga iinkwenkwezi, kunye nonxibelelwano lwe-optical. Le mpumelelo yophando ayiboneleli nje kuphela ngeengcinga ezintsha zophuhliso lwe-photodetectors zezinto eziphantsi, kodwa ikwabonelela ngeereferensi ezintsha zophando lwexesha elizayo kunye nophuhliso lwezixhobo ze-optoelectronic ezisebenzayo neziphantsi.