12899

1069 دكتري

دكتري

مخابرات (ميدان)

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1396

نه، 105ص.: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

رضا صفيان

اصغر غلامي

ابوالقاسم زيدآبادي نژاد، محسن مداح علي

1396/07/24

كتابنامه

برق و كامپيوتر

مهندسي برق و كامپيوتر

ID1069 دكتري

ترانزيستورهاي نوري هايبريد 63 2 6 4 آشكارسازهاي نوري در باند تراهرتز 63 2 6 5 مقايسه پارامترهاي عملياتي عددهاي شايستگي آشكارسازهاي مختلف نوري پايه گرافني 64 22 فصل سوم تحليل و طراحي يك آشكارساز پايه گرافني با استفاده از نانو توري هاي پلاسمونيكي استفاده از خاصيت ذاتي حامل هاي داغ در طراحي 34 روش حل پيشنهاد شده 44 تجمع بارها جهت محاسبه پتانسيل شيميايي در سرتاسر كانال 54 3 2 6 مقاومت افزاره 65 3 2 2 محاسبه جريان فوتو ترموالكتريكي 25 3 2 3 حالت خاص روش پيشنهادي 15 3 2 4 افزاره ارائه شده 61 نتيجه گيري 67 31 فصل چهارم تحليل و طراحي يك آشكارساز نوري پايه گرافني با تغذيه موجبر پلاسمونيكي هايبريد طراحي ساختار ارائه شده 37 لايه فوتونيكي 37 4 6 6 مدل تحليلي پيشنهاد شده براي محاسبه مقاومت افزاره 47 4 6 2 آشكارساز ارائه شده 77 جريان فوتو ترموالكتريكي 48 نتيجه گيري 78 88 فصل پنجم نتيجهگيري چكيده 88 پيشنهادهايي براي ادامه تحقيق 68 مراجع 66 نه هشت

61Incorporating Hot Carriers in Graphene based Plasmonic Photodetectors Seyed As ad Amirhosseini sa amirhoseyni@ec iut ac ir Date of Submission 9 7 2017 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 IranSupervisor Reza safian r safian@cc iut ac irAdvisor Dr Asghar Gholami gholami@cc iut ac irDepartment Graduate Program CordinatorAbstractGraphene has emerged as an appealing material for a variety of optoelectronic applications due to its uniqueelectrical and optical characteristics In this thesis we will present recent advances in plasmonic graphene based photodetectors and graphene boron nitride BN hetero structures with con ned optical architectures However low optical absorption of a bare graphene layer limits optical responsivity of a photodetector Hotelectron photo thermoelectric PTE effect is a promising detection mechanism in graphene basedphotodetectors Based on this effect hot carriers temperature pro le and Seebeck coef cient S create a PTEvoltage along the graphene channel Here we have used plasmonic nano gratings on top of the electrodes tocreate both strong eld distribution and asymmetric hot carrier spatial pro le along one side of graphenechannel simultaneously Therefore instead of limiting the device to work just by localizing heating on a speci cjunction using this design we can localize incoming radiation to a speci c location along the channel evenwith uniform incoming radiation Here we also proposed another solution to overcome absorption problem by using hybrid plasmonic waveguide HPW mechanism Covering the plasmonic layer in waveguide integrated con gurations with two high index contrast materials will result in a highly con ned hybridplasmonic mode between the metal surface and high index dielectric waveguide Keywords The photo thermoelectric effect Hot electron Hybrid plasmonic waveguide Graphene based photodetectors IntroductionGraphene as a new optoelectronic platform brings new functionalities including broadbandultrafast photodetection 1 2 The electronic heat capacity of a single layer graphene isextremely low which results in a higher change in temperature for the same absorbed energycompared to other bulk materials Till now Various photodetection schemes andarchitectures have been proposed The simplest one is metal graphene metal MGM architecture which also has supreme photoresponse mainly because of its ability to exploitboth photo thermoelectric and photovoltaic effects 3 4 However low optical absorptionof a bare graphene layer limits optical responsivity of a photodetector Following the initialphoto excitation by local heating a junction e g p n junction fast scattering processes likecarrier carrier scattering and slow cooling processes like phonon emission 5 generate hotcarriers Hot electron photo thermoelectric PTE effect is a promising detection mechanismin graphene based photodetectors Based on this effect hot carriers temperature profile Tel and Seebeck coefficient S create a PTE voltage along the graphene channel In fact

رضا صفيان

اصغر غلامي

ابوالقاسم زيدآبادي نژاد، محسن مداح علي