On the photoconductivity behavior of emeraldine-salt polyaniline films

Paiva, Aline Bastos de; Correr, G.I.; Ugucioni, Júlio César; Carvalho, Giovani Romeu; Jasinevicius, Renato Goulart; Godoy, Marcio Peron Franco de

doi:10.1016/j.synthmet.2021.116915

Cited by 11 publications

(9 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The photons seem to excite either the carrier from a band to a defect state or detrapping a defect state, which can then capture free carriers from the electronic bands [17]. From a qualitative point of view, the primary mechanism responsible for NPC is the ratio between recombination and generation rates in the presence of light [37]. The role of additional levels and/or bands on the photoconductivity mechanisms was previously modeled by Salis et al [38] and recently by Paiva et al [37] with a set of rate equations considering the presence of deep and shallow traps.…”

Section: Electro-optical Characteristicsmentioning

confidence: 99%

“…From a qualitative point of view, the primary mechanism responsible for NPC is the ratio between recombination and generation rates in the presence of light [37]. The role of additional levels and/or bands on the photoconductivity mechanisms was previously modeled by Salis et al [38] and recently by Paiva et al [37] with a set of rate equations considering the presence of deep and shallow traps. The nature of shallow traps responsible for the negative photoconductivity in AgO requires further systematic investigations.…”

Section: Electro-optical Characteristicsmentioning

confidence: 99%

See 1 more Smart Citation

The Negative Photoconductivity of Ag/AgO Grown by Spray-Pyrolysis

et al. 2022

View full text Add to dashboard Cite

The main goal of this work is to provide a general description of the negative photoconductivity effect observed in Ag/AgO films grown by the spray-pyrolysis technique. X-ray diffractograms display hybrid films with high texturized AgO and metallic Ag phases. Scanning electron microscopy images show small Ag particles on the surface. Due to its surface nature, X-ray photoelectron spectroscopy revealed the predominance of the metallic character of Ag 3d spectra as compared to Ag2+. Negative photoconductivity with photoresponse in the order of seconds is observed under several wavelengths of excitation. We found that the amplitude of the negative photoresponse is strongly dependent on the optical absorbance and enhanced by surface plasmon resonance. The low-cost technique employed and the special features regarding negative photoconductivity provide an exciting platform for developing optical-electronic devices with low power consumption.

show abstract

Section: Electro-optical Characteristicsmentioning

confidence: 99%

Section: Electro-optical Characteristicsmentioning

confidence: 99%

The Negative Photoconductivity of Ag/AgO Grown by Spray-Pyrolysis

et al. 2022

View full text Add to dashboard Cite

show abstract

“…In fact, most of the parameters needed to calculate the theoretical trap stiffness were carefully measured; they are the bead radius and height from the coverslip and the laser power and beam waist (the refractive index of PANI (1.8) was found in the literature). In addition, for PANI we have used an absorption coefficient α = 2300 cm –1 , compatible with the literature . Such a value of α provides the best agreement between the GO model and our experimental results, indicating that the PANI beads absorb considerably at the 1,064 nm wavelength used.…”

Section: Resultsmentioning

confidence: 99%

Use of Organic Semiconductors as Handles for Optical Tweezers Experiments: Trapping and Manipulating Polyaniline (PANI) Microparticles

Oliveira

Moura

Lucas

et al. 2023

ACS Appl. Polym. Mater.

View full text Add to dashboard Cite

Here we propose the use of the organic semiconductor polyaniline (PANI) for the preparation of spherical-shaped microparticles to serve as handles in optical tweezers (OT) experiments. The stable trapping and manipulation of PANI beads was demonstrated for the first time, using a Gaussian (TEM00) beam optical tweezers. The trap stiffness was characterized for various different parameters such as the bead radius, the laser power, and the distance between the bead and the coverslip of the sample chamber, attesting the viability of using such material for optical manipulation. Since the effective optical properties of PANI can be modulated by the synthesis process, some related applications are also proposed. The results of the present work therefore open the door for using semiconductor polymeric materials in OT applications.

show abstract

“…рис. 3) свідчить про допований стан ПАн у його плівках, а саме у формі емеральдинової солі (ЕмС) цитратної кислоти [47]. Зокрема, піки при ~340 та 840 нм, а також плече ~420 нм зумовлені π-π*, π-полярон і полярон-π* переходами, відповідно [48].…”

Section: визначення оптичної енергії ширини забороненої зониunclassified

Energy Band Gap and the Refractive Index for Polyaniline Thin Films of Polyaniline in Thin Films on Polyethylene Surface

Stetsiv¹,

Yatsyshyn²,

Reshetnyak³

2022

Proc. Shevchenko Sci. Soc. Chem. Sci.

View full text Add to dashboard Cite

e-mail: yuliia.stetsiv@lnu.edu.ua Polyaniline (PAn) films, doped with citric acid, were synthesized on a polyethylene substrate by chemical oxidative polymerization using ammonium peroxydisulfate as an oxidant. The influence of monomer concentration on the optical properties of PAn films was investigated. Optical band gap, absorption coefficient, extinction coefficient, refractive index were calculated as a function of wavelength. Different methods for determining the energy of the energy gap (Tauc method and absorption spectrum fitting) were considered. It was found that the optical band gap for all thin PAn films is due to the direct allowed optical transitions. It was found that the band gap of PAn films decreases with increasing thickness of deposited PAn films. It is established that the optical energies of the band gap of PAn films of different thickness, estimated by the results of optical absorption measurements using Tauc methods and absorption spectrum fitting, are practically commensurate and are in the range of 3.13–2.36 eV for film thicknesses equal to 18.7–137.4 nm, respectively. Based on the correlations between the optical energy of the band gap and the refractive index of semiconductors using Moss, Ravindra, Ravindra-Gupta, Reddy-Ahammed, Gerve-Vandamme, Kumar-Singh, Annani and Duffy-Reddy ratios, the value of the refractive index of PAn films was calculated and these results were compared with the values obtained from the experimental results. From the obtained results it is seen that the refractive index of PAn films increases with increasing polyaniline film thickness on a polyethylene substrate. The values obtained from the Ravindra and Ravindra-Gupta relations are the closest to the experimental ones. Therefore, the synthesized PE/PAn films can be an available material for the production of optoelectronic devices, for example, for organic field transistors and LEDs.

show abstract

On the photoconductivity behavior of emeraldine-salt polyaniline films

Cited by 11 publications

References 38 publications

The Negative Photoconductivity of Ag/AgO Grown by Spray-Pyrolysis

The Negative Photoconductivity of Ag/AgO Grown by Spray-Pyrolysis

Use of Organic Semiconductors as Handles for Optical Tweezers Experiments: Trapping and Manipulating Polyaniline (PANI) Microparticles

Energy Band Gap and the Refractive Index for Polyaniline Thin Films of Polyaniline in Thin Films on Polyethylene Surface

Contact Info

Product

Resources

About