TITLE

Spectroscopy and carrier dynamics in CdSe self-assembled quantum dots embedded in ZnxCdyMg1-x-ySe

AUTHOR(S)

Comanescu, G.; Wang, W. B.; Gundry, S.; Das, B.; Alfano, R. R.; Perez-Paz, M. N.; Tamargo, M. C.; Muñoz, M.; Popov, I.; Isaacs, L. L.

PUB. DATE

June 2005

SOURCE

Applied Physics Letters;6/20/2005, Vol. 86 Issue 25, p253113

SOURCE TYPE

Academic Journal

DOC. TYPE

Article

ABSTRACT

Time-resolved and steady-state photoluminescence, reflectivity, and absorption experiments were performed on CdSe quantum dots in ZnxCdyMg1-x-ySe barriers. Studies of the capture times of the photoexcited carriers into the quantum dots and of electron-hole recombination times inside the dots were performed. Photoluminescence rise time yielded capture times from 20 ps to 30 ps. All samples exhibit fast and slow photoluminescence decays, consistent with observing two independent but energetically overlapping decays. The faster relaxation times for the sample emitting in the blue range is 90 ps, whereas for the two samples emitting in the green it is 345 ps and 480 ps. The slower relaxation times for the sample emitting in blue is 310 ps, whereas for the samples emitting in green is 7.5 ns. These results are explained on the basis of the structural differences among the quantum-dot samples.

ACCESSION #

17636560

 

Related Articles

• Carrier transfer from wetting layer to quantum dots studied by cw-resolved and time-resolved photoluminescence in CdSe/ZnSe quantum dot system. Kim, Tae Soo; Lee, Byoung Woo; Oh, Eunsoon; Lee, Sanghoon; Furdyna, J. K. // Journal of Applied Physics;Mar2010, Vol. 107 Issue 6, p063517 

  We have studied the cw-resolved and time-resolved photoluminescence (PL) spectra of the CdSe quantum dots (QDs), where PL peaks from the “wetting layer” and from the QDs are observed. The temporal behavior of the PL spectra after a short-pulse laser excitation provides evidence of...

• Characterization of self-assembled InAs quantum dots with InAlAs/InGaAs strain-reduced layers by photoluminescence spectroscopy. Chang, K. P.; Yang, S. L.; Chuu, D. S.; Hsiao, R. S.; Chen, J. F.; Wei, L.; Wang, J. S.; Chi, J. Y. // Journal of Applied Physics;4/15/2005, Vol. 97 Issue 8, p083511 

  The optoelectronic characteristics of self-assembled InAs quantum dots (QDs) with strain-reduced layers (SRLs) were investigated using photoluminescence (PL) spectroscopy. Various SRLs that combine In0.14Al0.86As and In0.14Ga0.86As with the same total thickness were examined to ascertain their...

• Near-field spectroscopy of bimodal size distribution of InAs/AlGaAs single quantum dots. Young-Jun Yu; In-Taek Jeong; Jong-Chun Woo; Wonho Jhe // Applied Physics Letters;10/3/2005, Vol. 87 Issue 14, p143108 

  We report on high-resolution photoluminescence (PL) spectroscopy of size distribution of InAs/AlGaAs quantum dots (QDs) by using a near-field scanning optical microscope (NSOM). The double-peaked distribution of PL spectra is clearly observed, which is associated with the bimodal size...

• Quantum dot decoherence measured by ensemble photoluminescence. Gurioli, M.; Sanguinetti, S.; Mano, T.; Koguchi, N.; Nötzel, Richard // Journal of Applied Physics;11/15/2005, Vol. 98 Issue 10, p103527 

  We propose and experimentally demonstrate that a very simple, noninvasive, and common technique, i.e., standard nonresonant photoluminescence of large ensemble of quantum dots (QDs), can be used to determine the temperature dependence of homogeneous broadening. The method can be applied to a...

• Micro-photoluminescence of capped and uncapped ordered single InAs quantum dots on GaAs (311)B. Selçuk, E.; Hamhuis, G. J.; Nötzel, R. // AIP Conference Proceedings;1/4/2010, Vol. 1199 Issue 1, p535 

  Micro-photoluminescence (PL) of capped and uncapped ordered single InAs quantum dots (QDs) on patterned GaAs (311)B substrates exhibits distinct emission lines which are broadened for uncapped QDs. This indicates strong interaction with surface states paving the way towards high-sensitivity...

• Size dependent active effect of CdTe quantum dots on pyrogallol-H2O2 chemiluminescence system for chromium(III) detection. Kanwal, Shamsa; Xiaohong Fu; Xingguang Su // Microchimica Acta;Apr2010, Vol. 169 Issue 1/2, p167 

  Water-soluble CdTe quantum-dots (QDs) of different sizes and capped with mercaptosuccinic acid were prepared by the microwave irradiation method. The QDs can significantly enhance the chemiluminescence (CL) of the pyrogallol-H2O2 system. Those with a diameter of 3.8 nm produce the most intense...

• Ballistic electron emission luminescence spectroscopy of an InAs quantum dot heterostructure. Yi, Wei; Appelbaum, Ian; Russell, K. J.; Narayanamurti, V.; Hanson, M. P.; Gossard, A. C. // Applied Physics Letters;9/13/2004, Vol. 85 Issue 11, p1990 

  We present ballistic electron emission luminescence (BEEL) spectroscopy measurements of an InAs quantum dot (QD) heterostructure based on three-terminal hot electron injection using a scanning tunneling microscope (STM) and a planar tunnel-junction transistor. Due to higher injected current, the...

• Gain saturation in InP/GaInP quantum-dot lasers. Lutti, J.; Smowton, P. M.; Lewis, G. M.; Blood, P.; Krysa, A. B.; Lin, J. C.; Houston, P. A.; Ramsay, A. J.; Mowbray, D. J. // Applied Physics Letters;1/3/2005, Vol. 86 Issue 1, p011111 

  We have measured the gain-current and gain-quasi–Fermi level separation characteristics for InP/AlGaInP quantum-dot-laser structures. Saturation of the gain-current characteristics is apparent even though photoluminescence excitation spectroscopy measurements indicate that the 2D states...

• Quality factors of qubit rotations in single semiconductor quantum dots. Wang, Q. Q.; Muller, A.; Bianucci, P.; Shih, C. K.; Xue, Q. K. // Applied Physics Letters;7/18/2005, Vol. 87 Issue 3, p031904 

  The quality factors of quantum bit (qubit) rotations in single self-assembled quantum dots were investigated using photoluminescence spectroscopy. Rotations with azimuthal angle [lowercase_phi_synonym] along the equator of the qubit sphere were implemented by varying the time delay between two...

Read the Article