Two-photon-assisted excited state absorption in nanocomposite films of PbS stabilized in a synthetic glue matrix

被引：55

作者：

Kurian, Pushpa Ann ^{[1
]}

Vijayan, C.

Sandeep, C. S. Suchand

Philip, Reji

Sathiyamoorthy, K.

机构：

[1] Indian Inst Technol, Madras 600036, Tamil Nadu, India

[2] Raman Res Inst, Bangalore 560080, Karnataka, India

来源：

NANOTECHNOLOGY | 2007年 / 18卷 / 07期

关键词：

D O I：

10.1088/0957-4484/18/7/075708

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Strong nonlinear absorption is observed in nanocomposite films containing PbS nanocrystals of mean size of 3.3 nm stabilized in a commercial poly(vinyl acetate) glue by a novel and simple chemical route of synthesis. A significant blueshift of the optical absorption edge indicates strong quantum confinement. The mean nanocrystal size was characterized by x-ray diffraction and transmission electron microscopy. The surface structure of nanocrystals is analysed using infrared spectroscopy. The excitonic transitions are probed by photoacoustic spectroscopy and the results are analysed on the basis of theoretical calculations using envelope function formalism. Results of open aperture z-scan experiments suggest a model involving saturable absorption followed by two-photon absorption at a lower concentration while the data for a higher concentration fitted saturable absorption followed by three-photon absorption. Free carrier absorption due to two-photon-assisted excited state absorption appears to be the predominant mechanism of optical nonlinearity.

引用

页数：7

共 36 条

[1] The effect of surface modification on femtosecond optical Kerr effect of PBS nanoparticles [J].

Ai, XC ;

Guo, L ;

Zou, YH ;

Li, QS ;

Zhu, HS .

MATERIALS LETTERS, 1999, 38 (02) :131-135

[2] OPTICAL NONLINEARITY OF SEMICONDUCTOR-DOPED GLASSES AT FREQUENCIES BELOW THE BAND-GAP - THE ROLE OF FREE-CARRIERS [J].

BANFI, GP ;

DEGIORGIO, V ;

TAN, HM .

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS, 1995, 12 (04) :621-628

[3] QUANTUM CONFINEMENT OF PBS MICROCRYSTALS IN GLASS [J].

BORRELLI, NF ;

SMITH, DW .

JOURNAL OF NON-CRYSTALLINE SOLIDS, 1994, 180 (01) :25-31

[4] ELECTRON ELECTRON AND ELECTRON-HOLE INTERACTIONS IN SMALL SEMICONDUCTOR CRYSTALLITES - THE SIZE DEPENDENCE OF THE LOWEST EXCITED ELECTRONIC STATE [J].

BRUS, LE .

JOURNAL OF CHEMICAL PHYSICS, 1984, 80 (09) :4403-4409

[5] Preparation and characterization of nanocomposite thin films for optical devices [J].

Carotenuto, G ;

Her, YS ;

Matijevic, E .

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, 1996, 35 (09) :2929-2932

[6] Nonlinear optics for high-speed digital information processing [J].

Cotter, D ;

Manning, RJ ;

Blow, KJ ;

Ellis, AD ;

Kelly, AE ;

Nesset, D ;

Phillips, ID ;

Poustie, AJ ;

Rogers, DC .

SCIENCE, 1999, 286 (5444) :1523-1528

[7] FORMATION OF PBS NANOCLUSTERS USING REVERSED MICELLES OF LEAD AND SODIUM AEROSOL-OT [J].

EASTOE, J ;

COX, AR .

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, 1995, 101 (01) :63-76

[8] QUANTUM SIZE EFFECT IN SEMICONDUCTOR MICROCRYSTALS [J].

EKIMOV, AI ;

EFROS, AL ;

ONUSHCHENKO, AA .

SOLID STATE COMMUNICATIONS, 1985, 56 (11) :921-924

[9] Resonant nonlinear optical properties of PbS nanocrystals under nano-and picosecond pulsed laser excitation [J].

Fick, J ;

Schell, J ;

Levy, R ;

Martucci, A ;

Guglielmi, M .

PURE AND APPLIED OPTICS, 1997, 6 (05) :527-535

[10] Nonlinear optical properties of semiconductor-doped sol-gel waveguides [J].

Fick, J ;

Martucci, A ;

Guglielmi, M ;

Schell, J .

FIBER AND INTEGRATED OPTICS, 2000, 19 (01) :43-56

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