Size-dependent capacitance study on InGaN-based micro-light-emitting diodes

Yang, W. et al. (2014) Size-dependent capacitance study on InGaN-based micro-light-emitting diodes. Journal of Applied Physics, 116(4), 044512. (doi: 10.1063/1.4891233)

Abstract

We report a detailed study on size-dependent capacitance, especially the negative capacitance(NC), in InGaN-based micro-pixelated light-emitting diodes (micro-LEDs). Similar to conventional broad-area LEDs, micro-LEDs show NC under large forward bias. In the conventional depletion and diffusion capacitance regimes, a good linear relationship of capacitance with device size is observed. However, the NC under high forward bias shows slight deviation from above-mentioned linear relationship with device size. This behaviour can be understood if the effects of current density and junction temperature on NC are considered. The measured temperature dependence and frequency dispersion of the capacitance underpin this point of view. The NCs of two reference broad-area LEDs were also measured and compared with that of micro-LED clusters with the same total size. A stronger NC effect is observed in the micro-LED clusters, which is attributed to the increased number of sidewall defects during fabrication process.

• Item Type: Articles
• Keywords: GaN, size-dependent, capacitance, micro light-emitting diodes.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Mckendry, Dr Jonathan and Zhang, Dr Shuailong
• Authors: Yang, W., Zhang, S., McKendry, J. J.D., Herrnsdorf, J., Tian, P., Gong, Z., Ji, Q., Watson, I. M., Gu, E., Dawson, M. D., Feng, L., Wang, C., and Hu, X.
• Subjects: Q Science > QC Physics; T Technology > TK Electrical engineering. Electronics Nuclear engineering
• College/School: College of Science and Engineering > School of Engineering; College of Science and Engineering > School of Engineering > Biomedical Engineering
• Research Group: School of Engineering
• Journal Name: Journal of Applied Physics
• Journal Abbr.: JAP
• Publisher: American Institute of Physics
• ISSN: 0021-8979
• ISSN (Online): 1089-7550