Linear electro–optic tensor ratio determination and quadratic electro–optic modulation of electrostatically self-assembled CdSe quantum dot films

Zhang, Liangmin; Zhang, Fajian; Wang, Yongqiang; Claus, Richard O.
April 2002
Journal of Chemical Physics;4/8/2002, Vol. 116 Issue 14, p6297
Academic Journal
A new class of CdSe quantum dot-doped polymer films are synthesized using electrostatic layer-by-layer self-assembly processing technique. Transmission electron spectroscopy and electron beam diffraction results show that the diameter of the CdSe quantum dots is 2-3 nm and that the CdSe clusters possess a hexagonal structure. X-ray photoelectron spectroscopy allows determination of the concentration of the CdSe quantum dots within the resulting films. Linear electro-optic (Pockels) and quadratic electro-optic (Kerr) effect behavior of the films are investigated by using Mach-Zenhder interferometric and ellipsometric techniques, respectively. Linear electro-optic tensor ratios r[sub 333]/r[sub 113] of 4.3±0.2 were determined. Theoretical calculations of the quadratic electro-optic coefficients are proposed for the conventional ellipsometric technique. The orientational enhancement effect originating from the permanent dipole moment and induced dipole moment of the CdSe clusters is also discussed. From the analysis of experimental data, we determine that the typical reorientational time for a CdSe dot in these films to respond to a sinusoidal electric field is 17.5 ms.


Related Articles

  • Memory effect in cadmium telluride quantum dots doped ferroelectric liquid crystals. Kumar, A.; Prakash, J.; Khan, Mohd Taukeer; Dhawan, S. K.; Biradar, A. M. // Applied Physics Letters;10/18/2010, Vol. 97 Issue 16, p163113 

    A pronounced memory effect has been observed in cadmium telluride quantum dots (CdTe-QDs) doped ferroelectric liquid crystals (FLCs) by using dielectric and electro-optical methods. The memory effect has been attributed to the charge storage on the CdTe-QDs upon the application of dc bias across...

  • Synthesis of CdTe quantum dots using a heterogeneous process at low temperature and their optical and structural properties. Jose, R.; Biju, V.; Yamaoka, Y.; Nagase, T.; Makita, Y.; Shinohara, Y.; Baba, Y.; Ishikawa, M. // Applied Physics A: Materials Science & Processing;2004, Vol. 79 Issue 8, p1833 

    Luminescent CdTe quantum dots (QDots) have been synthesized through a low-temperature process employing a heterogeneous reaction between cadmium acetate and tri-n-octyl phosphine tellurium (TOPTe) in the presence of tri-n-octyl phosphine oxide (TOPO). UV-visible absorption spectra revealed that...

  • Efficient, visible organic light-emitting diodes utilizing a single polymer layer doped with quantum dots. Campbell, I. H.; Crone, B. K. // Applied Physics Letters;1/28/2008, Vol. 92 Issue 4, p043303 

    We demonstrate organic light-emitting diodes (OLEDs) using a single active layer consisting of CdSe/ZnS quantum dots (QDs) dispersed in poly (9,9-dioctylfluorene) (PFO). The diodes have an external quantum efficiency of ∼0.5% and reach 0.1 A/cm2 at 6.5 V. These results are comparable to...

  • Enhanced Spontaneous Emission of CdSe/ZnSe Quantum Dots in Monolithic II-VI Pillar Microcavities. Lohmeyer, H.; Sebald, K.; Kruse, C.; Hommel, D.; Gutowski, J. // AIP Conference Proceedings;2007, Vol. 893 Issue 1, p1147 

    The emission properties of CdSe/ZnSe quantum dots in ZnSe-based pillar microcavities are studied. All-epitaxial cavities made of ZnSSe and MgS/ZnCdSe superlattices with a single quantum-dot sheet embedded have been grown by molecular-beam epitaxy. Pillar structures with diameters down to 500 nm...

  • Quantum dots: An optical point of view. Gammon, Dan // Nature Physics;Nov2007, Vol. 3 Issue 11, p761 

    The article provides information on topics related to quantum dots. It has been noted that a quantum dot is commonly charge by inserting electrons. It could be use as a building block for future opto-electronic architectures. Furthermore, in optical transitions, quantum dots can be charged with...

  • Optically induced bistability in the mobility of a two-dimensional electron gas coupled to a... Shields, A.J.; O'Sullivan, M.P.; Farrer, I.; Ritchie, D.A.; Cooper, K.; Foden, C.L.; Pepper, M. // Applied Physics Letters;2/1/1999, Vol. 74 Issue 5, p735 

    Discusses the results of an electro-optical study of modulation doped field effect transistor in which quantum dots are placed close to the electron channel. Occurrence of large, persistent drop in the two-dimensional electron gas by brief optical illumination; Reduction of the number of...

  • Group-III intermixing in InAs/InGaAlAs quantum dots-in-well. Wang, Y.; Djie, H. S.; Ooi, B. S. // Applied Physics Letters;3/13/2006, Vol. 88 Issue 11, p111110 

    We report selective postgrowth band gap tuning of InAs/InGaAlAs quantum dots-in-well grown on InP substrate using impurity-free group-III intermixing. In contrast to most reported intermixing results, SixNy annealing cap results in a larger band gap blueshift than SiO2 annealing cap with a...

  • Coulomb Blockade in a Lateral Triangular Small Quantum Dot. Tkachenko, V. A.; Kvon, Z. D.; Tkachenko, O. A.; Baksheev, D. G.; Estibals, O.; Portal, J. C. // JETP Letters;12/25/2002, Vol. 76 Issue 12, p720 

    An AlGaAs/GaAs lateral quantum dot of triangular shape with a characteristic size L < 100 nm (the smallest size for dots of this type) containing less than ten electrons was studied theoretically and experimentally. Single- electron oscillations of the conductance G of this dot were measured at...

  • Numerical simulation study of electrostatically defined silicon double quantum dot device. Sulthoni, Muhammad Amin; Kodera, Tetsuo; Uchida, Ken; Oda, Shunri // Journal of Applied Physics;Sep2011, Vol. 110 Issue 5, p054511 

    Coupled quantum dots are of great interest for the application of quantum computing. The aspect needing attention is the preparation of well-defined quantum dots with small sizes and interdot distances. We propose a novel electrostatics method to form silicon double quantum dots....


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics