Reliable and Damage-Free Estimation of Resistivity of ZnO Thin Films for Photovoltaic Applications Using Photoluminescence Technique

Poornima, N.; Vimalkumar, T.V.; Rajeshmon, V. G.; Kartha, C. Sudha; Vijayakumar, K. P.

doi:10.1155/2013/105796

Cited by 4 publications

(2 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar property has been observed in In 2 S 3 nanospheres or thin films. [46][47][48] After deposition of an additional ZnS shell layer coating over the CIS cores, the QY of the red emission of the obtained CIS/ ZnS QDs was 6-8 fold enhanced and the peak wavelength was blue-shifted by 8-45 nm (Fig. 1g).…”

Section: Resultsmentioning

confidence: 99%

The composition effect on the optical properties of aqueous synthesized Cu–In–S and Zn–Cu–In–S quantum dot nanocrystals

Zhang

Wang

Yang

et al. 2015

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

Multiternary quantum dots (QDs), because of the large degree of freedom in their structure and composition, have a wide tunability in their bandgap but also exhibit an increased uncertainty and complexity in their optical properties. In this work, we synthesized the ternary Cu-In-S (CIS) and quaternary Zn-Cu-In-S (ZCIS) QDs with different composition ratios via a facile aqueous route. The CIS QDs show multi-peak photoluminescence with their peak intensity dependent on the Cu : In ratio, which was illustrated using a donor-acceptor pair recombination process. Upon incorporation of Zn into the CIS QDs under similar conditions, the acquired ZCIS QDs exhibit blue-shifted photoluminescence (PL) spectra with an enhanced emission intensity and a narrowed spectral width (∼100 nm). A comparative study reveals that, reducing the Cu : In ratio in the CIS QDs and increasing the Zn content in the alloyed ZCIS QDs are both feasible strategies for bandgap engineering, although the influences on optical properties of the QDs were different. The XRD and EDX spectra revealed that the widening of the bandgap of the ZCIS QDs was correlated with the alloyed nanostructures and the preferential substitution of Cu by Zn. Compared to the Cu : In ratio variation, incorporation of Zn into CIS QDs is an effective strategy to achieve a more homogeneous absorption band and a wide range of emission wavelength tunability. After ZnS shell coating, the ZCIS/ZnS QDs show a further enhanced PL intensity with a prolonged fluorescence lifetime. Unlike CIS QDs, the blue shift in PL upon the shell growth was not pronounced for ZCIS QDs, for which a surface reconstruction mechanism was proposed and discussed. Finally, the as-prepared ZCIS/ZnS QDs were employed for in vitro cell imaging and exhibited good biocompatibility to macrophage cells.

show abstract

Section: Resultsmentioning

confidence: 99%

The composition effect on the optical properties of aqueous synthesized Cu–In–S and Zn–Cu–In–S quantum dot nanocrystals

Zhang

Wang

Yang

et al. 2015

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…A similar property has been observed in In 2 S 3 nanospheres or thin films. [358][359][360] After deposition of an additional ZnS shell layer coating over the CIS cores, the QY of the red emission of the obtained CIS/ZnS QDs was 6-8 fold enhanced and the peak wavelength was blue-shifted by 8-45 nm ( Figure 5.1 d). The significant PL enhancement can be attributed to passivation of the surface defects by the ZnS shell.…”

Section: Synthesis Of Zn-cu-in-s (Zcis) Qdsmentioning

confidence: 99%

Synthesis and surface modification of quantum dots for biophotonics applications

Zhang¹

View full text Add to dashboard Cite

In the last two decades, quantum dots (QDs) have demonstrated great potential for biophotonics applications such as optical imaging and analytes sensing. For these purposes, cadmium-based (Cd-based) QDs are most commonly used because of their excellent optical properties, while cadmium-free (Cd-free) QDs are attracting increasing attention due to the low toxicity of their components. Generally, for use in biological fluids, QDs are either prepared using the aqueous synthesis method or the hot colloidal synthesis method followed by a phase transfer process. This thesis studies the preparation of water-dispersible Cd-based and Cd-free QD by using these two methods and explores their potential for biophotonics applications. First, this thesis presents a facile aqueous synthesis method for preparing the biofunctionalized Cd-based QDs. The CdTe QD nanocrystals were fabricated in a microfluidic chip by using protein molecules as coordination ligands. Compared to the conventional bench-top method, the microfluidic synthesis approach produced the CdTe QDs with enhanced stability and improved biofunctionalization efficiency. Another method of preparing the aqueous QDs, phase transfer of the QDs synthesized in organic solvents, was also examined. Hydrophilic ligands with different chain lengths and functional groups were applied to render the QDs water-dispersible by using the ligand exchange method. Each set of QDs capped with specific surface ligands displayed strengths and limitations in certain aspects of their physicochemical properties, and induced different cellular responses. To mitigate toxicity concerns in biophotonics applications, Zn-Cu-In-S QDs, which are quaternary and Cd-free QDs, were prepared using a facile aqueous synthesis method. The composition effect on their optical properties is demonstrated and correlated with the Abstract 5 evolution of their structure and energy band gap. Using the same strategy of composition control, Zn-Ag-In-S QDs with different emission wavelengths were synthesized in the organic phase and then transferred into the aqueous phase via the encapsulation method. The resulting water-dispersible ZAIS QDs exhibited bright photoluminescence and long fluorescence lifetime and were applied in temporally multiplexed imaging of cells. Finally, ZnO QDs, a type of Cd-free QDs made from wide-band-gap oxides, were prepared using the sol-gel method. Their optical properties were modified via chemical doping and photodoping techniques. Their redox-sensitive photoluminescence and plasmonic properties make them promising candidates for biosensing applications. In summary, this thesis covers the manipulation of optical properties, surface chemistry and biocompatibility of Cd-based and Cd-free QDs using versatile strategies in synthesis and surface modification processes, and demonstrates the potential of using these QDs in biophotonics applications.

show abstract

Synthesis, characterization and stability study of aqueous MPA capped CuInS2/ZnS core/shell nanoparticles

Jain

Bharti

Bhullar

et al. 2022

Journal of Luminescence

View full text Add to dashboard Cite

Reliable and Damage-Free Estimation of Resistivity of ZnO Thin Films for Photovoltaic Applications Using Photoluminescence Technique

Cited by 4 publications

References 53 publications

The composition effect on the optical properties of aqueous synthesized Cu–In–S and Zn–Cu–In–S quantum dot nanocrystals

The composition effect on the optical properties of aqueous synthesized Cu–In–S and Zn–Cu–In–S quantum dot nanocrystals

Synthesis and surface modification of quantum dots for biophotonics applications

Synthesis, characterization and stability study of aqueous MPA capped CuInS2/ZnS core/shell nanoparticles

Contact Info

Product

Resources

About