Two-Dimensional Nanocrystal Assemblies for Photocapacitive Devices

Mahadevu, R and Pandit, T and Samuel, JJ and Ghosh, U and Jana, B and Gupta, HK and Aetukuri, N and Pandey, A (2022) Two-Dimensional Nanocrystal Assemblies for Photocapacitive Devices. In: ACS Applied Electronic Materials, 5 (3). pp. 1770-1777.

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Abstract

We describe the emergence of photocapacitance in two-dimensional layered nanocrystal assemblies. Devices are electrically probed by the application of a lateral bias across interdigitated electrodes. We observe capacitive current-voltage characteristics that are individually absent in the nanocrystals. Besides the occurrence of a large zero-bias capacitance, the assemblies further show a transient negative capacitive behavior where the small signal capacitance is found to attain values over a ±100 nF range. We show that this system behaves as a damped anharmonic oscillator. Further, the bias dependence of capacitance, characteristics under asymmetric cycling, as well as its relationship with shunt resistance are consistent with the system attaining a transient negative capacitance while migrating around a single energy minimum. We show modulation of the capacitive behavior by incident light enabling the usage of these materials in a photocapacitive detector device.

Item Type:	Journal Article
Publication:	ACS Applied Electronic Materials
Publisher:	American Chemical Society
Additional Information:	The copyright for this article belongs to American Chemical Society.
Keywords:	2D; assemblies; nanocrystals; negative capacitance; photodetector; quantum dots
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	24 Apr 2023 10:19
Last Modified:	24 Apr 2023 10:19
URI:	https://eprints.iisc.ac.in/id/eprint/81282

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