Self-biasing effect in colour sensitive photodiodes based on double p-i-n a-SiC:H heterojunctions

Vieira, Manuela; Fantoni, Alessandro; Louro, Paula; Fernandes, M.; Schwarz, R.; Lavareda, G.; Carvalho, C. Nunes de

doi:10.1016/j.vacuum.2008.03.056

Cited by 26 publications

(13 citation statements)

References 9 publications

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“…4b the ratio between the spectral photocurrents under red, green and blue steady state illumination and without it (dark) are plotted. Results confirm that a self biasing effect occurs under an unbalanced photogeneration [10]. Blue optical bias enhances the spectral sensitivity in the long wavelength ranges and quenches it in the short wavelength range.…”

Section: Self Optical Amplificationsupporting

confidence: 59%

Photo‐sensing devices using a‐Si based materials

Fernandes¹,

Louro²,

Fantoni³

et al. 2011

Phys. Status Solidi (c)

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Amorphous Si/SiC stacked photodiodes working as photonic devices are reviewed. Several applications (imagers, wavelength division demultiplexing devices and optical amplifiers) are proposed. In the imagers scans speeds up to 10 K lines per second were achieved without degradation in resolution. In the Wavelength Division Demultiplexing devices transmission rates are of the order of 4 kbit/s. Optical amplification occurs under steady state irradiation where the polychromatic mixture of different colors is higher than the sum of the individual monochromatic contributions. Electrical models are present to support the sensing methodologies. Experimental and simulated results show that the tandem devices act as charge transfer systems. They filter, amplify, store and transport the photogenerated carriers, keeping its memory (colour, intensity and bit rate) without adding any optical pre‐amplifier or optical filter as in the standard p‐i‐n cells. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Section: Self Optical Amplificationsupporting

confidence: 59%

Photo‐sensing devices using a‐Si based materials

Fernandes¹,

Louro²,

Fantoni³

et al. 2011

Phys. Status Solidi (c)

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“…3, under front irradiation, it enhances mainly the spectral sensitivity in the mediumlong wavelength ranges (α V R =4.7, α V G =2.4). Violet radiation is absorbed at the top of the front diode, increasing the electric field at the back diode [22] where the red and part of the green incoming photons are absorbed (see Fig. 1).…”

Section: Contributedmentioning

confidence: 99%

“…When an external optical bias is applied to a double pin structure, its main influence is in the field distribution within the less photo excited sub-cell [21].The front cell, under long wavelength irradiation; the back cell, under short wavelength light and both, under medium steady state illumination. In comparison with thermodynamic equilibrium conditions (dark), the electric field under illumination is lowered in the most absorbing cell (self forward bias effect) while the less absorbing reacts by assuming a reverse bias configuration (self reverse bias effect).…”

mentioning

confidence: 99%

Logic functions based on optical bias controlled SiC tandem devices

Silva¹,

Vieira²,

Louro³

et al. 2014

Phys. Status Solidi C

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The purpose of this paper is the design of an optoelectronic circuit based on a‐SiC technology, able to act simultaneously as a 4‐bit binary encoder or a binary decoder in a 4‐to‐16 line configurations and show multiplexer‐based logical functions. The device consists of a p‐i′(a‐SiC:H)‐n/p‐i(a‐Si:H)‐n multilayered structure produced by PECVD. To analyze it under information‐modulated wave (color channels) and uniform irradiation (background) four monochromatic pulsed lights (input channels): red, green, blue and violet shine on the device. Steady state optical bias was superimposed separately from the front and the back sides, and the generated photocurrent was measured.Results show that the devices, under appropriate optical bias, act as reconfigurable active filters that allow optical switching and optoelectronic logic functions development providing the possibility for selective removal of useless wavelengths.The logic functions needed to construct any other complex logic functions are the NOT, and both or either an AND or an OR. Any other complex logic function that might be found can also be used as building blocks to achieve the functions needed for the retrieval of channels within the WDM communication link. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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“…Under front irradiation, the lightto-dark sensitivity is enhanced mainly in the long-medium wavelength ranges. Violet radiation is absorbed at the top of the front diode, increasing the electric field at the least absorbing cell [7], the back diode, where the red and part of the green channels generate optical carriers. So, red and green collection are strongly enhanced (a Rfront = 4.7, a Gfront = 2.4), the blue lightly increases (a Bfront = 1.3) and the violet one stays near its dark value (a vfront = 1.0).…”

Section: Optical Bias Amplificationmentioning

confidence: 99%