Effect of heat treatment on the photoluminescence of CdS nanocrystallites in cadmium-rich organic Langmuir Blodgett matrix

Narayanam, Pavan K.; Soni, Purvesh; Mohanta, P.; Srinivasa, R.S.; Talwar, S. S.; Major, S.S.

doi:10.1016/j.matchemphys.2013.01.022

Cited by 17 publications

(7 citation statements)

References 90 publications

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“…The weak peak 3 is attributed to the recombination of electrons trapped at shallow states due to cadmium interstitials and holes in the VB tail. 53 The high-intensity peak 1 dominates the PL spectrum of the bare CdS, suggesting a high rate of electron−hole recombination in deep trap states. The same three emission bands are also observed in the fitted PL spectra of the CdS/RGO composites (Figure 2c), where, compared to those of bare CdS, peaks 1 and 2 become much weaker, while peak 3 remains almost unaltered (Figure S9).…”

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confidence: 99%

“…To investigate the CT behavior in the nanocomposites, photoluminescence (PL) and surface photovoltage (SPV) spectroscopy were performed to obtain the energy distribution of localized states in the band gap of CdS. − The four samples including bare CdS, Cg 0 , Cg 2 , and Cg 4 (all of which show typical photocatalytic activities) have a broad PL emission in the range of 1.5–3.0 eV (Figure a). The broad emission bands of bare CdS were fitted to three bands centered at 2.0 (peak 1), 2.2 (peak 2), and 2.4 eV (peak 3); some emission bands below 2.0 eV associated with deep trap states (unfitted) are also observed (Figure b) . The intense peak 1 is ascribed to the recombination of holes in the VB tail and electrons in deep trap states generated by sulfur vacancies ( V S 2+ ) in the CdS nanocrystals (Table S2).…”

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confidence: 99%

“… , Taking into account the optical band gap of ∼2.2 eV, peak 2 is assigned to recombination of electrons and holes at the CB tail and the VB tail. The weak peak 3 is attributed to the recombination of electrons trapped at shallow states due to cadmium interstitials and holes in the VB tail . The high-intensity peak 1 dominates the PL spectrum of the bare CdS, suggesting a high rate of electron–hole recombination in deep trap states.…”

mentioning

confidence: 99%

“…The broad emission bands of bare CdS were fitted to three bands centered at 2.0 (peak 1), 2.2 (peak 2), and 2.4 eV (peak 3); some emission bands below 2.0 eV associated with deep trap states (unfitted) are also observed (Figure 2b). 53 The intense peak 1 is ascribed to the recombination of holes in the VB tail and electrons in deep trap states generated by sulfur vacancies (V S 2+ ) in the CdS nanocrystals (Table S2). 54,55 Taking into account the optical band gap of ∼2.2 eV, peak 2 is assigned to recombination of electrons and holes at the CB tail and the VB tail.…”

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confidence: 99%

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Interaction-Dependent Interfacial Charge-Transfer Behavior in Solar Water-Splitting Systems

et al. 2019

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Dual-band-gap systems are promising for solar water splitting due to their excellent light-harvesting capability and high charge-separation efficiency. However, a fundamental understanding of interfacial charge-transfer behavior in the dual-band-gap configuration is still incomplete. Taking CdS/reduced graphene oxide (CdS/RGO) nanoheterojunctions as a model solar water splitting system, we attempt here to highlight the interaction-dependent interfacial charge-transfer behavior based on both experimental observations and theoretical calculations. Experimental evidence points to charge transfer at the CdS–RGO interface playing a dominant role in the photocatalytic hydrogen production activity. By tuning the degree of reduction of RGO, the interfacial interaction, and, thereby, the charge transfer can be controlled at the CdS–RGO interface. This observation is supported by theoretical analysis, where we find that the interfacial charge transfer is a balance between the effective single-electron- and hole-transfer probability and the surface free electron and hole concentration, both of which are related to the surface potential and tailored by interfacial interaction. This mechanism is applicable to all systems for solar water splitting, providing a useful guidance for the design and study of heterointerfaces for high-efficiency energy conversion.

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Interaction-Dependent Interfacial Charge-Transfer Behavior in Solar Water-Splitting Systems

et al. 2019

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“…3a. The broad emission peak at around 415 nm is observed due to excitonic transition of CdS nanostructures [39]. An intense peak is also observed at 640 nm for pure CdS.…”

Section: Photoluminescence Studiesmentioning

confidence: 85%

Synthesis of CdS/CdSe Core/Shell Heterostructures Using Ultrasonic Assisted Sol–Gel Method

Kumar

Goswami

2019

Chemistry Africa

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Inverted type CdS/CdSe core/shell heterostructures were synthesized using ultrasonic assisted low cost and environmentally friendly sol-gel route. Cadmium chloride, thiourea and selenium dioxide were used as Cd, S and Se precursors, respectively. The core/shell heterostructures were analyzed by various techniques like X-ray diffraction, high resolution transmission electron microscope (HRTEM), photoluminescence and optical studies. X-ray diffractograms exhibit the cubic phase structure with its peaks shifting towards the lower angle due to compressive strain. Moiré fringes are observed in HRTEM images of CdS/CdSe core/shell heterostructure due to lattice mismatch between CdS and CdSe. The interplanar spacing of moiré fringes is found to be around 2.38 nm. Photoluminescence studies show the peak shifts towards the higher wavelength due to lattice mismatch between CdS and CdSe. Shift in absorption peak towards the higher wavelength makes them suitable for dye synthesized solar cells.

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Molecular Beam Epitaxy Deposition of In Situ O‐Doped CdS Films for Highly Efficient Sb₂(S,Se)₃ Solar Cells

Cai

Yang

et al. 2023

Adv Funct Materials

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Antimony selenosulfide (Sb2(S,Se)3) is considered as a promising light‐harvesting material and has been widely used in solar cells. For high‐efficiency Sb2(S,Se)3 solar cells, the most commonly used electron‐transporting layer of cadmium sulfide (CdS) is generally prepared by chemical bath deposition (CBD) approach. However, the hazardous waste liquid from the chemical bath and the sensitivity of the deposition process to the environment are challenges to practical applications. Herein, a molecular beam epitaxy deposition is reported to prepare CdS films, overcoming the drawbacks of CBD process. Furthermore, through introducing oxygen during the deposition of CdS, the sulfur vacancy defects generated in the vacuum deposition process are suppressed. The performance of Sb2(S,Se)3 solar cells is accordingly improved significantly. This improvement is attributed to the following aspects: i) the improved optical transmittance of CdS films. ii) The enhanced [hk1] orientation of Sb2(S,Se)3 absorber layer. iii) The improved heterojunction quality and suppressed carrier recombination. As a result, a power conversion efficiency of 8.59% for Sb2(S,Se)3 solar cells is achieved. This study provides a novel strategy for preparing electron‐transporting layers for efficient chalcogenide thin‐film solar cells and sheds new light on large‐area solar cell applications.

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Effect of heat treatment on the photoluminescence of CdS nanocrystallites in cadmium-rich organic Langmuir Blodgett matrix

Cited by 17 publications

References 90 publications

Interaction-Dependent Interfacial Charge-Transfer Behavior in Solar Water-Splitting Systems

Interaction-Dependent Interfacial Charge-Transfer Behavior in Solar Water-Splitting Systems

Synthesis of CdS/CdSe Core/Shell Heterostructures Using Ultrasonic Assisted Sol–Gel Method

Molecular Beam Epitaxy Deposition of In Situ O‐Doped CdS Films for Highly Efficient Sb₂(S,Se)₃ Solar Cells

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Effect of heat treatment on the photoluminescence of CdS nanocrystallites in cadmium-rich organic Langmuir Blodgett matrix

Cited by 17 publications

References 90 publications

Interaction-Dependent Interfacial Charge-Transfer Behavior in Solar Water-Splitting Systems

Interaction-Dependent Interfacial Charge-Transfer Behavior in Solar Water-Splitting Systems

Synthesis of CdS/CdSe Core/Shell Heterostructures Using Ultrasonic Assisted Sol–Gel Method

Molecular Beam Epitaxy Deposition of In Situ O‐Doped CdS Films for Highly Efficient Sb2(S,Se)3 Solar Cells

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Product

Resources

About

Molecular Beam Epitaxy Deposition of In Situ O‐Doped CdS Films for Highly Efficient Sb₂(S,Se)₃ Solar Cells