♠ 주제 : Surface Chemistry of Nanocrystal Quantum Dots

♠ 연사 : 정소희교수님 (성균관대학교 에너지과학과)        

♠ 일시 : 2021년 11월 30일 17:00~18:00   

♠ 초청 : 김상욱교수님(내선 2522)   

Abstract 

Until recently, originating from covalent nature in crystal bonding and the surface dangling bond as well as oxophillic nature of the element, synthesis and surface chemistry of III-V (InP, InAs, InSb) nanocrsytals are lagging behind compared to other ionic nanocrystals. In this presentation, I will present two specific challenges in III-V nanocrystal synthesis. First, we present covalent tetrapod InAs and InP nanocrystals as a crystalline “late intermediate” that warrants atomically controlled colloidal nanocrystal growth. We present the use of the late intermediate with well-defined facets at the sub-10 nm scale for directional growth with atomic control and highlight the potential for the new directed approach of nanocrystal synthesis. [1] Second, we present a route of synthesizing highly mono-dispersed InAs colloidal quantum dots in wide size-range by continuously introducing amorphous InAs nanoclusters as a single-source precursor on nanocrystal seeds. Our synthesis using InAs nanoclusters as a source of monomer resulted in induced focusing otherwise challenging with conventional precursors used for III-V quantum dot synthesis. Further, using a modified Fick’s law, we find that the growth of InAs QD is mainly dominated by the monomer diffusion dynamics and a continued precursor injection reduce the effective monomer concentration in the solution, lead to a decline of the monomer concentration gradient thus slow down the growth. Diffusion-dynamics-controlled chemical process finally provides a route of creating highly monodispersed InAs colloidal quantum dots enabling short-wavelength IR photon over 1700 nm. [2]

♠줌링크 

주제: MST6016_ 분자과학기술세미나Ⅱ(O1413-1) [정소희 교수님]

시간: 2021년 11월 23일  05:00 오후 서울

https://ajou-ac-kr.zoom.us/j/81042196008?pwd=Y3ZIazIra3VKQnkrYmtnejFMVkk0Zz09

회의 ID: 810 4219 6008

암호: 580753