Giant enhancement in photoresponse via engineering of photo-induced charge (electron and hole) transfer in linear and non-linear devices

Sai Manohar, GV and Krupanidhi, SB and Nanda, KK (2020) Giant enhancement in photoresponse via engineering of photo-induced charge (electron and hole) transfer in linear and non-linear devices. In: Sensors and Actuators, A: Physical, 304 .

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Abstract

Zinc oxide (ZnO) has been widely explored for UV detection despite its high exciton binding energy that can inhibit its photoresponse due to high probability of recombination. Here, we describe an approach that suppresses recombination and enhances the photoresponse via engineering of photo-induced charge transfer (PCT) in a linear MSM device Ag/ZnO/Ag and a non-linear p-Si/ZnO junction device. ZnO film when coated with carbon nanotubes (CNTs)/ nitrogen-doped CNTs (NCNTs) facilitates electron transfer and when coated with Poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) facilitates hole transfer, which inhibits recombination, increasing its photocurrent between 275�400 nm. This is one of the interesting approaches to enhance the photoresponse of a material. The extent of PCT depends on the amount of CNTs/NCNTs and PEDOT:PSS. Photocurrent was found to increase by �362-fold and �607-fold for 365 nm wavelength when NCNTs and NCNTs along with PEDOT:PSS were used as the recombination inhibitor on ZnO thin film, respectively. The responsivity was found to be 153 mA/W and 10.5 A/W, respectively for the coated Ag/ZnO/Ag linear and p-Si/ZnO non-linear device configurations, under 365 nm illumination. The enhancement is �15-fold for the non-linear devices. Overall, this work paves the way for an elegant and inexpensive means to hugely enhance photoresponse via engineering the photo-induced charge transfer in linear and non-linear devices. Furthermore, in addition to the photocurrent, the dark current and hence, the conductivity can be engineered via the approach discussed here. © 2020

Item Type:	Journal Article
Publication:	Sensors and Actuators, A: Physical
Publisher:	Elsevier Ltd
Additional Information:	The copyright of this article belongs to Elsevier Ltd
Keywords:	Binding energy; Carbon nanotubes; Charge transfer; Conducting polymers; Doping (additives); II-VI semiconductors; Metallic films; Photocurrents; Photodetectors; Semiconductor quantum wells; Silicon compounds; Styrene; Zinc oxide, Exciton-binding energy; Inexpensive means; Non-linear devices; Photo detection; Photo-induced charge; Photoinduced charge transfer; Poly(styrene sulfonate); Poly-3 ,4-ethylenedioxythiophene, Image enhancement
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	24 Jun 2020 07:02
Last Modified:	24 Jun 2020 07:02
URI:	http://eprints.iisc.ac.in/id/eprint/64794

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