Band gap variation of size-controlled ZnO quantum dots synthesized by sol–gel method

Lin, Kuo Feng; Cheng, Hsu-Yung; Hsu, Hsu Cheng; Liu, Lin; Hsieh, Wen‐Pin

doi:10.1016/j.cplett.2005.05.027

Cited by 458 publications

(170 citation statements)

References 32 publications

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“…From the quantum point of view, the electron is localized within a potential well of a given width. As the size of the nanoparticle is decreased, the width of the potential well decreases, and the energy levels are pushed up [3,9]. Experimental data indicated that actually the energy gap increases as the particle size is decreased and that the shape of nanoparticles may also affect the value of the energy gap [10].…”

Section: Figurementioning

confidence: 82%

“…The main difference between the bulk crystal and the nanocrystal derives from the small spatial extension of the crystal L, which should be smaller than a critical length ξ -typically of the order of 100 nanometers [1]. As the size of the nanocrystal L is reduced below this critical length, the energy levels of electrons are pushed up [1][2][3] (It is important to point that the energy levels are pushed out as the size of confinement is decreased even at larger scales-not solely at the nano scale. However, this effect is stronger at shorter distances).…”

Section: Infinite Crystal Versus Finite Crystalmentioning

confidence: 99%

See 1 more Smart Citation

Nanoparticles and Bacteria

Chipara¹,

Ibrahim²,

Yust³

et al. 2015

JNMR

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A concise critical review of the antibacterial features of some nanoparticles (metallic and oxide semiconductors) is presented. The review starts with a brief analysis of the physical features of nanoparticles and includes a discussion about the system nanoparticles-water-light, which is of utmost importance in biological and medical cases. Both metal and semiconducting nanoparticles are releasing electrons under the effect of the incoming electromagnetic radiation (light). This is the source of major misunderstandings as the antibacterial features of nanoparticles can be intrinsic (in this case antibacterial capabilities will be measured in the absence of light) or mediated (in this case the antibacterial features will be observed solely under light irradiation). The critical review opens the discussion about the need for experimental measurements in dark and under the effect of light-a type of research that was typically disregarded. The main ideas are supported by examples from specialty research. New concepts as specificity and effectiveness of antibacterial features are tentatively suggested.

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Section: Figurementioning

confidence: 82%

Section: Infinite Crystal Versus Finite Crystalmentioning

confidence: 99%

Nanoparticles and Bacteria

Chipara¹,

Ibrahim²,

Yust³

et al. 2015

JNMR

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“…The sample with smaller crystallite size has larger energy gap. This relationship was described by Lin et al (2005), [20] where the sample of ZnO quantum dot with a smaller diameter has a larger energy gap for the diameter varied from $ 3.5 to 12 nm. This result has been confirmed using a mass effective model based on Coulomb interaction and the data calculated using the model agreed well with the experimental data.…”

Section: Resultsmentioning

confidence: 99%

Effect of surfactant on the physical properties of ZnO nanorods and the performance of ZnO photoelectrochemical cell

Rahman

Umar

Taslim

et al. 2013

Journal of Experimental Nanoscience

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The performance of photoelectrochemical cell (PEC) strongly depends on the physical properties of photovoltaic material. Polyvinylpyrrolidone (PVP), cetyltrimethylammonium bromide (CTAB) and hexamethylenetetramine (HMT) surfactants were used to modify the morphology nanostructure of ZnO films by a simple technique, namely, ammonia-assisted controlled hydrolysis technique during their growth process. The film treated with PVP, CTAB and HMT produce the nanostructure shape of nanoflower, nanowire and nanorod (NR), respectively. These ZnO samples were utilised as photovoltaic materials in a PEC of FTO (fluorine tin oxide)/ZnO/electrolyte/platinum. It was found that the photovoltaic parameters such as short-circuit current density (J sc ), open-circuit voltage (V oc ) and fill factor (FF) are influenced by the morphology in term of shape and particle size and optical property of the ZnO NR. The PEC utilising the ZnO sample treated with HMT surfactant demonstrated the highest J sc of 0.47 mAcm À2, V oc of 0.46 V, FF of 29.2% and h of 0.06%, respectively, since it possesses the lowest energy gap.

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“…Sol-gel method Sol-gel method, one of the widely used wet chemical methods in synthesizing various nanomaterials [15,[73][74][75], has been used for fabrication of ZnO QDs [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. Among a number of reports on fabrication of ZnO QDs over the past decades, sol-gel method was the mostly used one due to its simplicity and cheapness.…”

Section: Chemical Methods On Synthesis Of Zno Qdsmentioning

confidence: 99%

“…By far, various kinds of synthetic approaches have been realized in fabricating such small ZnO QDs, which can be roughly divided into chemical methods and physical methods. Chemical methods involves sol-gel method [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40], hydrothermal growth [41][42][43][44], thermal decomposition [45][46][47][48][49][50], electrochemical method [51][52][53][54], while physical methods involves PLA or PLD [55][56][57][58][59], MOCVD [60][61][62][63], sputtering [64][65][66], FSP method [67][68][69][70] and VPT deposition [71,72]. At present, all the methods can be divided into two parts as follow:…”

Section: Synthesis Of Zno Qdsmentioning

confidence: 99%