logo

korean english

게시판

Home > 게시판 > 세미나

아래와 같이 콜로퀴움을 개최하오니 많이 참석해 주시기 바랍니다.
420분부터 제1과학관 31214 e+강의실에서 다과를 준비하오니 많은 참석 부탁드립니다

 

아 래

 

제목Contribution of Internal and Surface Traps to Blinking Statistics in Colloidal Quantum Dots

 

연사: 국   양 교수님 (서울대학교 자연과학대학 물리천문학부)

                                        

일시: 2014년 5월 7() 오후4:30

 

장소: 1과학관 31214  첨단e+강의실

 

초록: Colloidal quantum dots (QDs) have been successfully developed into nanoscale light sources with variable wavelength. However, fluorescence intermittency (FI), also known as photoluminescence blinking, remains a major problem. FI was first observed seventeen years ago in a QD1. It is now thought that trap states in the QD play a major role in the origin of FI. However, proposed microscopic models still give contradictory predictions, mainly due to the lack of information on the spatial and energetic distribution of traps. We observed internal and surface trap states for the first time using scanning tunneling microscopy and spectroscopy. Internal defects induce tens to hundreds of midgap electronic states within every QD. Surface traps appear as charged quantum islands at some ligand molecules. We found that trapping and detrapping dynamics among internal and surfaces traps are important for understanding FI statistics. By performing a Monte Carlo simulation that includes the measured spatial and energetic distribution of the internal and the surface traps, we demonstrate the characteristic power-law statistics of FI. Two types of FI dynamics observed in a recent spectroelectrochemistry experiment2 can also be successfully explained with our internal-surface trap-distribution model. We anticipate this observation to become a corner stone for the complete elimination of FI.

 

[1] A. L. Efros, M. Rosen, Phys. Rev. Lett. 78, 1110 (1997).

[2] C. Galland, Y. Ghosh, A. Steinbrück, M. Sykora, J.A. Hollingsworth, V.I. Klimov, H. Htoon. Nature 479, 203–207 (2011).

 

 

번호 제목 날짜 조회 수
공지 <12/8(Thu.) 11:00am>노벨상 소개 강연 - 2016년 노벨 물리학상: 위상 응집 물리의 탄생 2016.11.28 1057376
322 <11/6> Graphene plasmon and Plasmonics 2013.10.31 234737
321 <11/13> Computer-Aided Engineering for Nucleic Acid Nanostructures 2013.11.07 106163
320 <11/20> 마침내 발견된 신의 입자: 힉스 보존 2013.11.14 71837
319 <11/27> Introduction to Terahertz and Infrared Spectroscopy 2013.11.21 88699
318 <12/4> Shining light on the dark Universe 2013.11.29 174183
317 <12/11> Is Nature Natural? 2013.12.05 66809
316 2014학년도 1학기 콜로퀴움 일정 2014.03.03 102414
315 <3/12> Where, when and how atomic nuclei were cooked in universe? 2014.03.07 86635
314 <3/19> 고자기장 하에서 반도체 양자구조의 광전이 특성 2014.03.13 73797
313 <3/26> Shedding infrared light on high-Tc superconductors 2014.03.19 95156
312 <4/2> Radio Detection of Ultra High Energy Cosmic Rays and Neutrinos in Antarctica 2014.03.26 166460
311 <4/9> Quantum oscillations at the LHC 2014.04.03 93187
310 <4/16> Lasers, Microscopes, and Superconductors: Laser Scanning Microscopy of Superconducting Circuits 2014.04.10 104327
309 <4/30> Physical principles and applications of ultrasound in diagnostics and therapy 2014.04.22 69355
» <5/7> Contribution of Internal and Surface Traps to Blinking Statistics in Colloidal Quantum Dots 2014.04.30 87506
307 <5/14> Synthesis of Two Dimensional Materials by Chemical vapor deposition 2014.05.07 92620
306 <5/21> Magnetism and Superconductivity 2014.05.14 110618
305 <5/28> The hunt for high energy neutrinos with IceCube - more evidence for their astrophysical origin 2014.05.22 108539
304 <6/11> Advanced Physiological Optics and Its Ophthalmic Applications 2014.05.28 230046
303 <5/30(금)> 입자물리이론 그룹 미니 워크숍 개최 안내 2014.05.29 98212