Enhanced near-infrared response of nano- and microstructured silicon/organic hybrid photodetectors

Derek V, Glowacki ED, Sytnyk M, Heiß W, Marcius M, Ristic M, Ivanda M, Sariciftci NS (2015)


Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2015

Journal

Publisher: American Institute of Physics (AIP)

Book Volume: 107

Article Number: 083302

Journal Issue: 8

DOI: 10.1063/1.4929841

Abstract

Heterojunctions between an organic semiconductor and silicon are an attractive route to extending the response of silicon photodiodes into the near infrared (NIR) range, up to 2000nm. Silicon-based alternatives are of interest to replace expensive low band-gap materials, like InGaAs, in telecommunications and imaging applications. Herein, we report on the significant enhancement in NIR photodetector performance afforded by nano- and microstructuring of p-doped silicon (p-Si) prior to deposition of a layer of the organic semiconductor Tyrian Purple (TyP). We show how different silicon structuring techniques, namely, electrochemically grown porous Si, metal-assisted chemical etching, and finally micropyramids produced by anisotropic chemical etching (Si μP), are effective in increasing the NIR responsivity of p-Si/TyP heterojunction diodes. In all cases, the structured interfaces were found to give photodiodes with superior characteristics as compared with planar interface devices, providing up to 100-fold improvement in short-circuit photocurrent, corresponding with responsivity values of 1-5mA/W in the range of 1.3-1.6μm. Our measurements show this increased performance is neither correlated to optical effects, i.e., light trapping, nor simply to geometric surface area increase by micro- and nanostructuring. We conclude that the performance enhancement afforded by the structured p-Si/organic diodes is caused by a yet unresolved mechanism, possibly related to electric field enhancement near the sharp tips of the structured substrate. The observed responsivity of these devices places them closer to parity with other, well-established, Si-based NIR detection technologies.

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How to cite

APA:

Derek, V., Glowacki, E.D., Sytnyk, M., Heiß, W., Marcius, M., Ristic, M.,... Sariciftci, N.S. (2015). Enhanced near-infrared response of nano- and microstructured silicon/organic hybrid photodetectors. Applied Physics Letters, 107(8). https://doi.org/10.1063/1.4929841

MLA:

Derek, Vedran, et al. "Enhanced near-infrared response of nano- and microstructured silicon/organic hybrid photodetectors." Applied Physics Letters 107.8 (2015).

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