https://scholars.lib.ntu.edu.tw/handle/123456789/356652
Title: | Carrier dynamics in GaN layers overgrown on nanocolumnar structures | Authors: | Wang, H.-C. Tang, T.-Y. CHIH-CHUNG YANG Malinauskas, T. Jara?iunas, K. |
Keywords: | Carrier recombination; GaN; MOVPE; Nanostructures; Photoluminescence; Time-resolved experiments | Issue Date: | 2010 | Journal Volume: | 7 | Journal Issue: | 7-8 | Start page/Pages: | 1856-1858 | Source: | Physica Status Solidi (C) Current Topics in Solid State Physics | Abstract: | We report on photoelectrical and optical properties of the GaN layers overgrown on the columnar structure with diameter of columns varying from 250 to 600 nm. Excess carriers were injected to 2-ìm thick overgrown layer by an interference pattern of two picosecond laser beams at 355 nm. Carrier recombination and diffusion was monitored by time-resolved transient grating technique and provided 3-4 fold increase of carrier lifetime (up to ∼500 ps) with respect to that in the GaN template. Even stronger increase of carrier lifetime at excess carrier density of ∼1019 cm-3 was observed both in the overgrown layers and substrate and attributed to saturation of electron trapping centers by free carriers. A factor of 7-8 stronger time-integrated photoluminescence intensity (at 363 nm) also confirmed the increased structural quality of the overgrown layers, what correlated well with the enhanced electrical parameters. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA. |
URI: | http://www.scopus.com/inward/record.url?eid=2-s2.0-77955836280&partnerID=MN8TOARS http://scholars.lib.ntu.edu.tw/handle/123456789/356652 https://www.scopus.com/inward/record.uri?eid=2-s2.0-77955836280&doi=10.1002%2fpssc.200983455&partnerID=40&md5=3b719d47288b879c976982a7afcf838a |
ISSN: | 18626351 | DOI: | 10.1002/pssc.200983455 | SDG/Keyword: | Carrier dynamics; Carrier recombination; Columnar structures; Electrical parameter; Electron trapping; Excess carriers; Free carriers; GaN; GaN layers; GaN template; Interference patterns; MOVPE; Picosecond laser; Structural qualities; Time-integrated photoluminescence; Time-resolved; Transient grating technique; Gallium alloys; Gallium nitride; Nanostructures; Optical properties; Photoluminescence; Carrier lifetime |
Appears in Collections: | 電機工程學系 |
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