In-Plane Anisotropic Photoconduction in Nonpolar Epitaxial a-Plane GaN

Pant, Rohit and Shetty, Arjun and Chandan, Greeshma and Roul, Basanta and Nanda, K K and Krupanidhi, S B (2018) In-Plane Anisotropic Photoconduction in Nonpolar Epitaxial a-Plane GaN. In: ACS APPLIED MATERIALS & INTERFACES, 10 (19). pp. 16918-16923.

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Abstract

Nonpolar a-plane GaN epitaxial films were grown on an r-plane sapphire using the plasma-assisted molecular beam epitaxy system, with various nitrogen plasma power conditions. The crystallinity of the films was characterized by high-resolution Xray diffraction and reciprocal space mapping. Using the X-ray ``rocking curve-phi scan'', 0002],1-100], and 1-102] azimuth angles were identified, and interdigitated electrodes along these directions were fabricated to evaluate the direction-dependent UV photoresponses. UV responsivity (R) and internal gain (G) were found to be dependent on the azimuth angle and in the order of 0002] > 1-102] > 1-100], which has been attributed to the enhanced crystallinity and lowest defect density along 0002] azimuth. The temporal response was very stable irrespective of growth conditions and azimuth angles. Importantly, response time, responsivity, and internal gain were 210 ms, 1.88 A W-1, and 648.9%, respectively, even at a bias as low as 1 V. The results were validated using the Silvaco Atlas device simulator, and experimental observations were consistent with simulated results. Overall, the photoresponse is dependent on azimuth angles and requires further optimization, especially for materials with in-plane crystal anisotropy.

Item Type:	Journal Article
Publication:	ACS APPLIED MATERIALS & INTERFACES
Publisher:	AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
Additional Information:	Copy right for this article belong toAMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
Department/Centre:	Division of Chemical Sciences > Materials Research Centre Division of Electrical Sciences > Electrical Communication Engineering
Date Deposited:	05 Jun 2018 15:47
Last Modified:	05 Jun 2018 15:47
URI:	http://eprints.iisc.ac.in/id/eprint/59954

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