Copyright 2004 by Marcel Dekker, Inc. All Rights Reserved.

More documents

Recommendations

Info

Figure 3 Schematic of a three-pulse (pump–postpump–probe) experiment and theexcitation/relaxation processes monitored in it. An e–h pair is created via an interbandexcitation with a pump pulse in the visible spectral range. The electron is reexcitedwithin the conduction band by an IR postpump pulse. The electron relaxationback to the ground state is monitored with a third pulse, probing interband absorptionchanges.(diamonds in Fig. 4b), the relaxation constant is 250 fs, which is close to thevalue measured for ZnS-capped NQDs. With increasing reexcitation time, theelectron relaxation time gradually increases up to 3 ps at Dt IR = 430 fs (trianglesin Fig. 4b). A further increase in Dt IR does not lead to significantchanges in electron intraband dynamics [compare traces taken at Dt IR = 430fs (triangles) and 600 fs (squares); Fig. 4b]. Importantly, the threshold delay ofroughly 400 fs found in these experiments is very close to the hole-transfertime to a capping molecule inferred from two-pulse TA measurements [31].This observation indicates that dramatic changes in electron relaxation resultfrom hole transfer to the surface pyridine group, strongly suggesting thatelectron relaxation is dominated by e–h interactions (Auger-type e–h energytransfer).Copyright 2004 by Marcel Dekker, Inc. All Rights Reserved.
Figure 4 Dynamics of the IR postpump-induced 1S bleaching changes (electronintraband relaxation) detected at different delay times (Dt IR ) between the visiblepump and IR postpump pulses for ZnS-capped (a) and pyridine-capped (b) CdSeNQDs (R = 1.15 nm) (symbols are experimental data points; lines are singleexponentialfits).Copyright 2004 by Marcel Dekker, Inc. All Rights Reserved.
Page 1:
Copyright 2004 by Marcel Dekker, In
Page 4 and 5:
Page 6 and 7:
Page 8 and 9:
This book covers several topics of
Page 10 and 11:
esult, some exciting topics were no
Page 12 and 13:
3. Fine Structure and Polarization
Page 14 and 15:
9. III-V Quantum Dots and Quantum D
Page 16 and 17:
ContributorsUri BaninThe Hebrew Uni
Page 18 and 19:
1‘‘Soft’’ Chemical Synthesi
Page 20 and 21:
structure of energy states leads to
Page 22 and 23:
growth can proceed by Ostwald ripen
Page 24 and 25:
Figure 3 Transmission electron micr
Page 26 and 27:
Figure 4 Temporal evolution of the
Page 28 and 29:
No. 26, are f85% (Fig. 6) [21]. Alt
Page 30 and 31:
tion spectra and broad PL spectra.
Page 32 and 33:
ing surface-to-volume ratio with di
Page 34 and 35:
Figure 8 Photoluminescence spectra
Page 36 and 37:
lattice mismatch. Such a large latt
Page 38 and 39:
match between InAs and ZnS of f11%.
Page 40 and 41:
successfully repeated for up to thr
Page 42 and 43:
Under a different growth regime, on
Page 44 and 45:
Figure 14 Atomic model of the CdSe
Page 46 and 47:
‘‘Teardrop-shaped’’ particl
Page 48 and 49:
Figure 17 High-resolution TEMs of C
Page 50 and 51:
allows isolation of tetrapods in f8
Page 52 and 53:
ligand concentrations yield a reduc
Page 54 and 55:
een determined and quantitatively c
Page 56 and 57:
tion volumes were also shown to be
Page 58 and 59:
synthesis temperatures of z400jC ar
Page 60 and 61:
Figure 23 (a) Photoluminescence spe
Page 62 and 63:
levels (fV1 Mn per NQD). Despite in
Page 64 and 65:
Figure 25 X-ray diffraction pattern
Page 66 and 67:
Figure 27 Transmission electron mic
Page 68 and 69:
An additional factor that strongly
Page 70 and 71:
Figure 30 (a,b) Schematics illustra
Page 72 and 73:
Slow, controlled precipitation of h
Page 74 and 75:
Figure 34 Schematic illustrating th
Page 76 and 77:
Page 78 and 79:
achieving biological compatibility
Page 80 and 81:
47. Yu H.; Gibbons P.C.; Kelton K.F
Page 82 and 83:
2Electronic Structure inSemiconduct
Page 84 and 85:
Figure 2 (a) Simple model of a nano
Page 88 and 89:
electron and hole to be treated as
Page 90 and 91:
independently, Eq. (13) is commonly
Page 92:
a better description of the bulk ba
Page 95 and 96:
investigated. For optical experimen
Page 97 and 98:
Figure 4 (a) Absorption (solid line
Page 99 and 100:
Figure 6 Normalized PLE scans for s
Page 101 and 102:
Figure 8 A simplistic model for des
Page 103 and 104:
Figure 10 Theoretically predicted p
Page 105 and 106:
Figure 12 Schematics depicting the
Page 107 and 108:
Figure 14 Calculated band-edge exci
Page 109 and 110:
Figure 15 Absorption (solid line) a
Page 111 and 112:
Figure 18 (a) Calculated band-edge
Page 113 and 114:
IV.BEYOND CdSeA. Indium Arsenide Na
Page 115 and 116:
the six-band Luttinger Hamiltonian.
Page 117 and 118:
11. Norris, D.J.; Efros, Al.L.; Ros
Page 119 and 120:
69. Gaponenko, S.V.; Woggon, U.; Sa
Page 121 and 122:
formation of a long-lived dark exci
Page 123 and 124:
where the constant A is determined
Page 125 and 126:
In crystals for which the function
Page 127 and 128:
The respective wave functions areC
Page 129 and 130:
passive, as was shown in Ref. 12. T
Page 131 and 132: square of the matrix element of the
Page 133 and 134: where e F = e F ieV and e F F = e x
Page 135 and 136: see that for all nanocrystal shapes
Page 137 and 138: optical recombination of the excito
Page 139 and 140: B. Recombination of the Dark Excito
Page 141 and 142: where x = cos h and f = l B g e H/3
Page 143 and 144: The theory of the polarization memo
Page 145 and 146: Figure 7 The size dependence of the
Page 147 and 148: state would have an infinite lifeti
Page 149 and 150: crystal axis [see Eq. (40)]. As a r
Page 151 and 152: time of the exciton momentum relaxa
Page 153 and 154: One must also account for the influ
Page 155 and 156: observed in one of the first studie
Page 157 and 158: REFERENCES1. Bawendi, M.G.; Wilson,
Page 159 and 160: 4Intraband Spectroscopyand Dynamics
Page 161 and 162: The solid line in Fig. 1 shows the
Page 163 and 164: Figure 2 FTIR spectra of n-type CdS
Page 165 and 166: of the center frequency. The experi
Page 167 and 168: limit given by radiative relaxation
Page 169 and 170: from a long lifetime due to the pho
Page 171 and 172: are two natural approaches to study
Page 173 and 174: 32. Inoshita, T.; Sakaki, H. Physic
Page 175 and 176: continuous spectral tunability over
Page 177 and 178: function and envelope function mome
Page 179 and 180: ottleneck’’ [14,28]. Further re
Page 181: in NQDs is dominated by nonphonon e
Page 185 and 186: Figure 5 (a) Time-resolved PL spect
Page 187 and 188: Figure 6 (a) The time delay of the
Page 189 and 190: and due to Auger-type e-h interacti
Page 191 and 192: Figure 9 Dynamics of the 1S bleachi
Page 193 and 194: significantly greater than the fast
Page 195 and 196: Figure 11 (a) Pump-intensity-depend
Page 197 and 198: NQD size. For small NQD sizes (R =
Page 199 and 200: Figure 14 Nonlinear absorption/gain
Page 201 and 202: sorption change associated with a s
Page 203 and 204: where n h em is the hole ‘‘emit
Page 205 and 206: ultrafast (subpicosecond to picosec
Page 207 and 208: Figure 18 Schematic of transitions
Page 209 and 210: Figure 19 Dynamics of pump-induced
Page 211 and 212: where n i (i=1, 2 . . . , N ) is th
Page 213 and 214: Figure 21 (a) Two-e-h-pair (biexcit
Page 215 and 216: the volume fraction (filling factor
Page 217 and 218: intensity dependence of this peak (
Page 219 and 220: Copyright 2004 by Marcel Dekker, In
Page 221 and 222: can contribute to the saturation of
Page 223 and 224: Copyright 2004 by Marcel Dekker, In
Page 225 and 226: coupling between ‘‘volume’’
Page 227 and 228: numerous discussions on the photoph
Page 229 and 230: 53. Kang, K.; Kepner, A.; Gaponenko
Page 231 and 232: the ‘‘on-off ’’ emission in
Page 233 and 234:
parallel form of data acquisition i
Page 235 and 236:
Figure 3 (a) Spectral time trace of
Page 237 and 238:
transition energies. In fact, these
Page 239 and 240:
distribution (dark line) does not d
Page 241 and 242:
exposure to only room light. In our
Page 243 and 244:
statistics for the off times are in
Page 245 and 246:
230Shimizu and BawendiCopyright 200
Page 247 and 248:
Figure 10 (a) Time trace of a CdSe(
Page 249 and 250:
and excited QD core states to fluct
Page 251 and 252:
arrows indicate the on-time truncat
Page 253 and 254:
W. K. Woo and V. C. Sundar for assi
Page 255 and 256:
size allows the electron affinity a
Page 257 and 258:
II.THEORY OF ELECTRON TRANSFER BETW
Page 259 and 260:
For the specific case of charge tra
Page 261 and 262:
dominates, the mobility is often fi
Page 263 and 264:
where the constant A and the temper
Page 265 and 266:
components of modulation which are
Page 267 and 268:
nanocrystals [41], understanding ph
Page 269 and 270:
and ionization potential through tw
Page 271 and 272:
quantum dots. Furthermore, because
Page 273 and 274:
For many applications, a host mater
Page 275 and 276:
form blends with morphologies that
Page 277 and 278:
Figure 11 Photoluminescence efficie
Page 279 and 280:
Figure 12 (a) Room-temperature PIA
Page 281 and 282:
discussed briefly in Section IV. Ch
Page 283 and 284:
dithiolates to thiol-terminated DNA
Page 285 and 286:
Films of passivated CdSe nanocrysta
Page 287 and 288:
Figure 16 Photocurrent action spect
Page 289 and 290:
decay with stretched exponential ki
Page 291 and 292:
siderably larger than might be esti
Page 293 and 294:
dispersing CdSe nanocrystal chromop
Page 295 and 296:
memory and charge storage effects [
Page 297 and 298:
all) of the optically excited elect
Page 299 and 300:
composites of nanocrystals and conj
Page 301 and 302:
55. Asbury, J.B.; Hao, E.C.; Wang,
Page 303 and 304:
108. Morgan, N.Y.; Leatherdale, C.A
Page 305 and 306:
The approaches to fabrication of se
Page 307 and 308:
Figure 1 Experimental realization o
Page 309 and 310:
Due to this voltage division, the m
Page 311 and 312:
Figure 3 Simulated tunneling spectr
Page 313 and 314:
electron charging. In both positive
Page 315 and 316:
Figure 5 shows the typical features
Page 317 and 318:
Figure 7 Map of levels for InAs nan
Page 319 and 320:
Figure 8 Scanning electron microsco
Page 321 and 322:
D CB = 0.31 eV is thus obtained. On
Page 323 and 324:
Figure 11 Correlation of optical an
Page 325 and 326:
atomistic approach based on pseudop
Page 327 and 328:
charging indicated that the tunneli
Page 329 and 330:
capacitance values were also kept t
Page 331 and 332:
could not be detected in the QD/DT/
Page 333 and 334:
Figure 18 Tunneling conductanceF sp
Page 335 and 336:
data in the inset of Fig. 19 repres
Page 337 and 338:
corresponding to the s-like wave fu
Page 339 and 340:
7. Grabert, H.; Devoret, M.H., Eds.
Page 341 and 342:
66. Su, B.; Goldman, V.J.; Cunningh
Page 343 and 344:
dimensional confinement are created
Page 345 and 346:
Figure 1 Transmission electron micr
Page 347 and 348:
The room-temperature absorption and
Page 349 and 350:
narrower in samples with larger mea
Page 351 and 352:
GaInP 2 QDs from a plot of the squa
Page 353 and 354:
crystal, indicating lattice-matched
Page 355 and 356:
Figure 5 Evolution of Stranski-Kras
Page 357 and 358:
Page 359 and 360:
Page 361 and 362:
C. Efficient Anti-Stokes Photolumin
Page 363 and 364:
Because HF treatment has been shown
Page 365 and 366:
Page 367 and 368:
intensity of the PL when it is on a
Page 369 and 370:
eV stems from recombining carriers
Page 371 and 372:
Figure 16 Model to explain two-colo
Page 373 and 374:
although this term is not rigorousl
Page 375 and 376:
10 ps (about an order of magnitude
Page 377 and 378:
electron relaxation is inhibited an
Page 379 and 380:
Page 381 and 382:
QDs, the nature of the QD capping s
Page 383 and 384:
QD solution. For an interdot distan
Page 385 and 386:
emission spectra of the two individ
Page 387 and 388:
Figure 23 Change of the PL intensit
Page 389 and 390:
(viz. the absorbed light intensity)
Page 391 and 392:
Figure 25Impact ionization in QDs.m
Page 393 and 394:
prevent electron-hole recombination
Page 395 and 396:
36. Miller, R.D.J.; McLendon, G.; N
Page 397 and 398:
91. Vurgaftman, I.; Singh, J. Appl.
Page 399 and 400:
139. Mićić, O.I.; Ahrenkiel, S.P.
Page 401 and 402:
10Synthesis and Fabrication of Meta
Page 403 and 404:
Figure 2 (A-C) Progression of HR-TE
Page 405 and 406:
Figure 3 Schematic for gold nanocry
Page 407 and 408:
Nanocrystal growth can occur by two
Page 409 and 410:
on the other hand, provide an ensem
Page 411 and 412:
Figure 6 (a) SAXS patterns for disp
Page 413 and 414:
Figure 8 The gold nanocrystal film
Page 415 and 416:
of the stabilizing ligand, and the
Page 417 and 418:
successfully modeled the 2D island
Page 419 and 420:
2. Steric Stabilization and a Soft
Page 421 and 422:
are fully extended. Moving away fro
Page 423 and 424:
Figure 11 High-resolution SEM image
Page 425 and 426:
Figure 13 (A) Transmission electron
Page 427 and 428:
function of the density of localize
Page 429 and 430:
Figure 15 High-resolution SEM image
Page 431 and 432:
thiol-capped nanocrystals [2]. The
Page 433 and 434:
41. Ackerson, B.J. Nature 1993, 365
Page 435 and 436:
with the effect of the particle com
Page 437 and 438:
Figure 1a shows the surface plasmon
Page 439 and 440:
Figure 2 (a) Ultraviolet-visible ab
Page 441 and 442:
agents [34]. The short-wavelength b
Page 443 and 444:
Figure 4 (a) Plot of the plasmon ab
Page 445 and 446:
the framework of traditional Mie’
Page 447 and 448:
show that effects due to the surrou
Page 449 and 450:
is located at the position of the g
Page 451 and 452:
Page 453 and 454:
Figure 8 Ultraviolet-visible absorp
Page 455 and 456:
laser pulses while being mixed in t
Page 457 and 458:
Figure 10 shows HR-TEM images of go
Page 459 and 460:
Page 461 and 462:
final irradiation product. At the s
Page 463 and 464:
following the laser excitation appe
Page 465 and 466:
36. Papavassiliou, G.C. Prog. Solid
Page 467 and 468:
particles to expand. Because the he
Page 469 and 470:
was frequency doubled in a 1-mm B-
Page 471 and 472:
Figure 2 Frequency of the acoustic
Page 473 and 474:
Figure 3 Change in radius (DR/R) ve
Page 475 and 476:
In this model, the electrons couple
Page 477 and 478:
Figure 5 Transient bleach data for
Page 479 and 480:
Figure 7 (a) Transient bleach data
Page 481 and 482:
that the particles with >80% Au hav
Page 483 and 484:
3. Del Fatti, N.; Valle´e, F.; Fly
show all

Copyright 2004 by Marcel Dekker, Inc. All Rights Reserved.

Create successful ePaper yourself

Delete template?

Save as template?