Absorption saturation and self-action processes under resonant excitation of the basic exciton transition in CdSe/ZnS colloidal quantum dots

Днепровский, В. С.; Zhukov, E. A.; Kozlova, M. V.; Wumaier, Tuerdi; Hieu, Dau Sy; Артемьев, М. В.

doi:10.1134/s106378341009026x

Cited by 13 publications

(4 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For many physical considerations of light‐matter interaction, it is sufficient to take only two energy eigenstates into account, namely, the states

| 1 ⟩

and

| 2 ⟩

with the energy difference

E_{2} - E_{1}

close to the incident light photon energy

ℏ ω

. The pair states can be two levels in atoms, spin‐split states in the magnetic resonance, tunneling two‐level systems in dielectric glasses, the ground electron and hole quantum‐confined levels in semiconductor quantum dots, etc. In such systems, the saturation of resonant optical properties is controlled by two characteristic times, longitudinal and transverse relaxation times

T_{1}

and

T_{2}

, respectively (

T_{2} \leq 2 T_{1}

).…”

Section: Introductionmentioning

confidence: 99%

Nonlinear Absorption and Photocurrent in Weyl Semimetals

Leppenen

Ivchenko

Golub

2019

Physica Status Solidi (b)

View full text Add to dashboard Cite

A theory of light absorption and circular photocurrent in Weyl semimetals is developed for arbitrary large light intensities with account for both the elastic and inelastic relaxation processes of Weyl fermions. The direct optical transition rate is shown to saturate at large intensity, and the saturation behavior depends on the light polarization and on the ratio of the elastic and inelastic relaxation times. The linear‐circular dichroism in absorption is shown to exceed 10% at intermediate light wave amplitudes and fast energy relaxation. At large intensity I, the light absorption coefficient drops as 1/I, and the circular photogalvanic current increases as I.

show abstract

“…For many physical considerations of light‐matter interaction, it is sufficient to take only two energy eigenstates into account, namely, the states

| 1 ⟩

and

| 2 ⟩

with the energy difference

E_{2} - E_{1}

close to the incident light photon energy

ℏ ω

T_{1}

and

T_{2}

, respectively (

T_{2} \leq 2 T_{1}

).…”

Section: Introductionmentioning

confidence: 99%

Nonlinear Absorption and Photocurrent in Weyl Semimetals

Leppenen

Ivchenko

Golub

2019

Physica Status Solidi (b)

View full text Add to dashboard Cite

show abstract

“…The PCE means the ratio of the total photon number of the red or green emission light to the total number of the blue exciting light, which is determined by many complicated factors, such as, concentration of QDs in IJP-ink or QDs photoresist and the thickness of QDCC layers. Although increasing the thickness of QDCC layers will reduce the BLT, the PCE will be reduced to a great degree due to the effect of QDs self-absorption [8]. Such tradeoff needs to be fully taken in account.…”

Section: Methodsmentioning

confidence: 99%

39.3: Hybrid Full‐Color Micro‐LED Display with Quantum Dots Color Conversion by Using Inkjet‐Printing and Photo‐Lithography Methods

Gu¹,

Wang²,

Jiang³

et al. 2021

Symp Digest of Tech Papers

View full text Add to dashboard Cite

show abstract

“…The measured angles of self-diffracted beams coincide with that calculated. We suppose that periodic change of nonlinear absorption arising as a consequence of state-filling and Stark shift of exciton transition 3,4 in CdSe/ZnS QDs creates amplitude grating. The nonlinear change of absorption is accompanied by nonlinear change of refraction and phase transient grating also may arise due to small shift from the excitation resonance wavelength 5 .…”

Section: Qd2mentioning

confidence: 99%

Degenerate four-wave mixing and two-photon induced gratings in colloidal quantum dots CdSe/ZnS

2015

Self Cite

View full text Add to dashboard Cite

The features of nonlinear and electro-optical processes has been discovered in the case of two-photon resonant excitation of the excitons in colloidal CdSe/ZnS quantum dots. Self-diffraction arises for two laser beams intersecting in the cell with colloidal CdSe/ZnS quantum dots (QDs) due to the dynamic phase grating formatting. The calculated induced change in the refractive is sufficient to form a phase diffraction grating. Such a large value of χ (3) as compared to the third-order nonlinear susceptibility for the solvent (hexane) is due to the increase in χ (3) occurring when the intermediate resonance is attained in a medium transparent for laser radiation. In order to identify physical processes responsible for the induced grating formation and the diffraction efficiency self-diffracted pulse intensity dependences on the incident pulse intensity were measured for two samples of colloidal QD CdSe/ZnS, which frequency of the fundamental exciton transition is tuned to the high-frequency and low-frequency region from the double laser frequency. The discovered cubic dependence of the self-diffracted pulse intensity on the incident pulse intensity was explained by four-wave mixing process. Discovered above 5-th index of power dependence of the self-diffracted pulse intensity on the excitation pulses intensity we explained by the increasing magnitude of two-photon absorption (due to shifting of two photons energy of laser radiation to the exact exciton absorption resonance by red Stark shift of the exciton absorption), accompanied by the growth absorption by two-photon excited carriers that leads to the induced amplitude grating formation in addition to the phase grating.

show abstract

Absorption saturation and self-action processes under resonant excitation of the basic exciton transition in CdSe/ZnS colloidal quantum dots

Cited by 13 publications

References 17 publications

Nonlinear Absorption and Photocurrent in Weyl Semimetals

Nonlinear Absorption and Photocurrent in Weyl Semimetals

39.3: Hybrid Full‐Color Micro‐LED Display with Quantum Dots Color Conversion by Using Inkjet‐Printing and Photo‐Lithography Methods

Degenerate four-wave mixing and two-photon induced gratings in colloidal quantum dots CdSe/ZnS

Contact Info

Product

Resources

About