Size-dependent photoluminescence of PbS QDs embedded in silicate glasses

Su, G.H.; Liu, Chao; Deng, Zhao; Zhao, Xiujian; Zhou, Xuedong

doi:10.1364/ome.7.002194

Cited by 41 publications

(34 citation statements)

References 53 publications

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“…For CdSe QDs, this shift decreases with the increase in radius of QDs, and disappears beyond a certain radius . As the position of the defect states is size‐dependent, this verifies the theoretical models that the energy level of defect states changes as the size of QDs increases inducing a size‐dependent Stokes shift . However, such size‐dependent Stokes shift was not observed, probably due to the small size in molecules or clusters, where the Stokes shift originates from the energy difference of the ground state vibrational levels …”

Section: Resultssupporting

confidence: 71%

“…44,45 As the position of the defect states is size-dependent, this verifies the theoretical models that the energy level of defect states changes as the size of QDs increases inducing a size-dependent Stokes shift. 46,47 However, such size-dependent Stokes shift was not observed, probably due to the small size in molecules or clusters, where the Stokes shift originates from the energy difference of the ground state vibrational levels. 45 A similar phenomenon was observed when one of the surface Cd atoms of the pristine cluster was bonded with another atom.…”

Section: Resultsmentioning

confidence: 99%

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Understanding the atomic and electronic structures origin of defect luminescence of CdSe quantum dots in glass matrix

Liu

et al. 2019

J Am Ceram Soc

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Well‐defined density functional theory (DFT) calculations are performed as the first exploratory study for the atomic and electronic mechanism of defect mediated morphology and optical properties of CdnSen (n = 3, 10, 13, and 33) quantum dots (QDs) in inorganic amorphous matrix. The intrinsic defects of pristine CdSe QDs, and the interfacial defects between the QDs and surrounding amorphous matrix, were systematically studied. The calculated electronic structure suggested that the pristine CdSe QDs capped by the structural modifiers or non‐bridging oxygen in the amorphous matrix gave rise to the structure reconstruction and paired defect states at the edge of the valence and conduction bands. The orbital analysis elucidated that the redistribution of the majority of HOMO and LUMO electron density was localized over the bonds formed by capping atoms and QDs. These changes in the electronic structures were further demonstrated by CdSe QDs embedded sodium silicate glasses. It turned out that Se atoms at QDs/glass interface were much more active than those found on the surface of organically passivated CdSe QDs. The results serve as a new paradigm in materials research to explore structural origins of defect emission from QDs and a new strategy to develop glasses containing QDs with high photoluminescence quantum efficiency.

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Section: Resultssupporting

confidence: 71%

Section: Resultsmentioning

confidence: 99%

Understanding the atomic and electronic structures origin of defect luminescence of CdSe quantum dots in glass matrix

Liu

et al. 2019

J Am Ceram Soc

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“…Due to the large specific surface area of the QDs, there are a large number of dangling bonds of Pb and Se on the surface of the QDs, and these dangling bonds form surface trap states (STS) located at Δ E 1 below the 1S e state of PbSe QDs . According to the results of the research, the energy position and energy distribution (Δ E 2 ) of defect states (DS) was closely related to the size of QDs . For small size Sr 2+ ‐doped PbSe QDs, The DS is widely distributed and lies below the STS.…”

Section: Resultsmentioning

confidence: 95%

“…For large size Sr 2+ ‐doped PbSe QDs, due to the quantum confinement effect, the band gap of QDs rapidly reduce. And the defect states rapidly increase and move above 1Se and Δ E 2 becomes smaller . The STS is mainly composed of some dangling bonds.…”

Section: Resultsmentioning

confidence: 98%

Photodarkening and anti‐Stokes photoluminescence from PbSe and Sr²⁺‐doped PbSe quantum dots in silicate glasses

et al. 2018

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Photoluminescence (PL) properties of PbSe and Sr2+‐doped PbSe quantum dots (QDs) doped in silicate glasses were investigated by changing the excited laser wavelength and intensity. When BaO was replaced by SrO, the Sr2+‐doped PbSe QDs formed and showed large blue‐shifts in both absorption and PL bands compared to the PbSe QDs. It is attributed to the increasing in band gap resulted by the incorporation of Sr2+ ions into PbSe QDs. These two kinds of QDs were excited by the laser with the wavelengths of 1319 and 1532 nm. When rising the pumping intensity up to 1000 mW, the PL intensity from Sr2+‐doped PbSe QDs monotonically increased, while, the PL intensity from PbSe QDs reached maximum at pumping intensity at ~200 mW (λex = 1319 nm) and ~300 mW (λex = 1532 nm). The good resistance to photodarkening of Sr2+‐doped PbSe QDs is indicated passivation effect on the surface defects from Sr2+ ions doping. For Sr2+‐doped PbSe QDs the anti‐Stokes photoluminescence (ASPL) were observed when using both 1319 and 1532 nm excitation. The integrated intensity of the ASPL is linear with the excitation intensity, which indicates that the ASPL belongs to the phonon‐assisted one‐photon process. And the ASPL intensity as a function of excitation intensity shows a size dependence of the QDs.

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“…Using QDs of different compositions allows adjusting the spectral range of the detector depending on the absorption region of the QD . Interest in using QDs is also due to the ease of the adjustment of the optical properties of the QD by changing its size . Ag 2 S has a relatively narrow bandgap of 1.0 eV in bulk and a high concentration of trap states, and the presence of which is associated with QD nonstoichiometry .…”

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confidence: 99%

Room Temperature Silicon Detector for IR Range Coated with Ag₂S Quantum Dots

Tretyakov

Shurakov

Ryabchun

et al. 2019

Physica Rapid Research Ltrs

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For decades, silicon has been the chief technological semiconducting material of modern microelectronics and has a strong influence on all aspects of the society. Applications of Si‐based optoelectronic devices are limited to the visible and near infrared (IR) ranges. For photons with an energy less than 1.12 eV, silicon is almost transparent. The expansion of the Si absorption to shorter wavelengths of the IR range is of considerable interest for optoelectronic applications. By creating impurity states in Si, it is possible to cause sub‐bandgap photon absorption. Herein, an elegant and effective technology of extending the photo‐response of Si toward the IR range is presented. This approach is based on the use of Ag2S quantum dots (QDs) planted on the surface of Si to create impurity states in the Si bandgap. The specific sensitivity of the room temperature zero‐bias Si_Ag2S detector is 1011 cm √Hz W−1 at 1.55 μm. Given the variety of available QDs and the ease of extending the photo‐response of Si toward the IR range, these findings open a path toward future studies and development of Si detectors for technological applications. The current research at the interface of physics and chemistry is also of fundamental importance to the development of Si optoelectronics.

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Size-dependent photoluminescence of PbS QDs embedded in silicate glasses

Cited by 41 publications

References 53 publications

Understanding the atomic and electronic structures origin of defect luminescence of CdSe quantum dots in glass matrix

Understanding the atomic and electronic structures origin of defect luminescence of CdSe quantum dots in glass matrix

Photodarkening and anti‐Stokes photoluminescence from PbSe and Sr²⁺‐doped PbSe quantum dots in silicate glasses

Room Temperature Silicon Detector for IR Range Coated with Ag₂S Quantum Dots

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Size-dependent photoluminescence of PbS QDs embedded in silicate glasses

Cited by 41 publications

References 53 publications

Understanding the atomic and electronic structures origin of defect luminescence of CdSe quantum dots in glass matrix

Understanding the atomic and electronic structures origin of defect luminescence of CdSe quantum dots in glass matrix

Photodarkening and anti‐Stokes photoluminescence from PbSe and Sr2+‐doped PbSe quantum dots in silicate glasses

Room Temperature Silicon Detector for IR Range Coated with Ag2S Quantum Dots

Contact Info

Product

Resources

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Photodarkening and anti‐Stokes photoluminescence from PbSe and Sr²⁺‐doped PbSe quantum dots in silicate glasses

Room Temperature Silicon Detector for IR Range Coated with Ag₂S Quantum Dots