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 1030263
226 <11/28> 별이 빛나는 밤에… 2012.11.22 69813
225 <12/5> 과학용어와 의학용어에 숨겨진 이야기 2012.11.28 70221
224 <12/12> 자성체의 스커미온 동역학 2012.12.06 69670
223 2013학년도 1학기 콜로퀴움 일정 2013.02.19 69616
222 <3/13> Quantum computing using solid state nano-devices 2013.03.08 66574
221 <3/20> 빛 : 우주의 신비를 푸는 열쇠 2013.03.14 67710
220 <3/27> Proximity effects and low dimensional superconductivity of Pb nano-islands  2013.03.21 75880
219 <4/3> 내 안의 파장을 바꿔라! 2013.03.29 65695
218 <4/10> Mapulation of spins in organic compounds 2013.04.03 87929
217 <4/17> Probing Stellar Explosions with Radioactive Beams* 2013.04.10 89569
216 <5/1> Entanglement and topological order in 1D and 2D systems 2013.04.18 96477
215 <5/8> Complex Networks: Through the 3D Looking Glass 2013.05.02 83106
214 <5/15> Quantum Critical Superconductivity 2013.05.09 68828
213 <5/22> Computer-based Mathematical Analysis and Applications to Physics (컴퓨터 기반 수리해석과 물리학에의 응용) 2013.05.15 121219
212 <5/29> Study on the electronic interactions in solids under high magnetic fields 2013.05.23 85378
211 <6/5> 물리학도가 증권가로 간 까닭은... 2013.05.29 68327
210 <6/12> Latest Results from the IceCube Neutrino Observatory 2013.06.07 87849
209 2013학년도 2학기 콜로퀴움 일정 2013.09.06 81183
208 <9/11> Epitaxial Oxygen Sponge 2013.09.09 89575
207 <9/25> 청각의 물리학: 어떻게 노이즈를 극복하는가? 2013.09.16 118134