Electrical and photoelectrical characteristic investigation of a new generation photodiode based on bromothymol blue dye (original) (raw)
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SDÜ Fen Bilimleri Enstitüsü Dergisi, 2017
In this study, the photovoltaic device application of bromothymol blue (BTB) as an organic interlayer has been reported. After Al back contact fabrication on the surface of the chemically cleaned substrate by thermal evaporation method, the organic interlayer has been grown on pSi substrate via spin coating technique. Al top contacts have been formed on this organic thin film to finalize the device constructions. The different illumination intensities were exposed to the prepared sample for the enhancement in the photovoltaic properties of device. The fundamental photovoltaic parameters such as open circuit voltage (Voc), short circuit current (Isc) and output power (P) were determined for the device under different illuminations. The photocurrent and the photo voltage have been increased with the increasing in illumination intensity. The dependence of the capacitance on the voltage at high and low frequency has been also reported for the studied device. Consequently, it has been confirmed that the illumination intensity has an important influence on the photovoltaic parameters of the device.
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Physica E: Low-dimensional Systems and Nanostructures, 2017
In this work, it is shown that choosing an organic-on-inorganic Schottky diode for photoconductive sensing by a using a power law exponent (PLE or determined at a single bias point is a limited approach. The standard literature approach does not highlight any bias voltage effects on the distribution of interface state density and other operationally important parameters. In this paper we suggest a new empirical method that holistically highlights the variation of with voltage, irradiance and temperature to reach a more informed choice of photosensor for real applications. We obtain a simple, plausible relation of the variation of barrier height, Φ, with voltage, irradiance and temperature. The method is evaluated with data collected previously for Schottky diodes of structure Al/p-Si/organic-semiconductor (OSC)/Au, where OSC is Coumarin-doped with graphene oxide (GO), Cobalt Phthacyanine (CoPC) doped with GO or PCBM doped with GO, respectively. The method reproduces published data for the three diodes reported at specific bias and provides for the first time some qualitative evidence of barrier height variation with light intensity, for which a possible physical basis is also given. Typically, Schottky barrier height is characterized using dark current leading to an under reporting of the effect of illumination on barrier height. Finally, 2 since recombination mechanisms are gauged on the basis of the magnitude of PLE, the method facilitates the identification of the recombination mechanism at a given bias.
Journal of Materials Science: Materials in Electronics, 2020
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Microelectronic Engineering, 2011
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High-Performance, Solution-Processed Non-polymeric Organic Photodiodes
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1 wileyonlinelibrary.com COMMUNICATION metrology, photometry and position sensing. However, these devices involve the deposition of multiple layers (up to 32 layers) and require the use of the expensive molecular beam technique. Recently, solution-processed small molecular or non-polymeric OPDs have also been demonstrated. However, the performance thus far has fallen behind their polymeric and/or evaporated small-molecular counterparts, especially in terms of detectivity, broad spectral response, and responsivity.
STUDY OF ORGANIC SEMICONDUCTOR BASED PHOTOVOLTAIC DEVICES: LIGHT SENSORS AND SOLAR CELLS
Recently, organic photovoltaic devices (OPVDs) have been extensively studied and demonstrated as promising candidates for light sensing applications. The novel materials are used in optoelectronic applications, utilizing their intrinsic physical, chemical and electrical characteristics. Organic semiconductors offer many physical and chemical properties that can be easily tailored by incorporating functional groups or manipulating physical conditions to meet specific requirements. The best feature of organic semiconductors is their solution processability at room temperature using simple and low cost deposition techniques. Aiming at the interesting properties of organic semiconductors, in this thesis, we have extensively explored organic semiconductors based solar cells and light sensors for optoelectronic applications. Dye sensitized photo sensors using water soluble organic photo sensitizer, Nickel (II) phthalocyaninetetrasulfonic acid tetrasodium salt (NiTsPc) have been fabricated and investigated. Two different types of TiO2 films (untreated and NaOH-treated) are prepared to serve as anodes for the sensors. Both films are subsequently sensitized by NiTsPc using aqueous solution. Commercially available Iodolyte Z100 and platinum coated indium doped tin oxide (ITO) are used as electrolyte and cathode, respectively. The NaOH-treated sensor demonstrates 2.81 times increase in sensitivity in terms of photo-conductivity as compared to the untreated sensor. The NaOH-treated sensor, however, surpasses the other sensor in terms of response/recovery times and stability in plateau values of the photocurrent. The proposed photosensor is eco-friendly and economical for commercial applications. A binary blend of two polymers, poly[2,6-(4,4-bis-(2-ethylhexyl)-4Hcyclopenta [2,1-b;3,4-b']dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT) and poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) as a sensitizer has been employed for a visible light dye sensitized photo sensor (DSPS). The proposed combination of the polymers covers almost the entire visible light spectrum.