Physics-based modeling and experimental implications of trap-assisted tunneling in InGaN/GaN light-emitting diodes

• Published in: Physica status solidi. A, Applications and materials science Vol. 212; no. 5; pp. 947 - 953
• Main Authors: Mandurrino, Marco, Verzellesi, Giovanni, Goano, Michele, Vallone, Marco, Bertazzi, Francesco, Ghione, Giovanni, Meneghini, Matteo, Meneghesso, Gaudenzio, Zanoni, Enrico
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 01.05.2015; Wiley Subscription Services, Inc
• Subjects: Density; Diodes; Gallium nitrides; GaN; Indium gallium nitrides; InGaN; Light-emitting diodes; Mathematical models; phonon-assisted transitions; Point defects; Silicon carbide; trap-assisted tunneling; Tunneling
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.201431743

In a combined experimental and numerical investigation, we present the effects of trap‐assisted tunneling on the sub‐threshold forward bias characteristics of a blue InGaN/GaN single‐quantum‐well LED test structure grown on a SiC substrate. The different role of donor‐ and acceptor‐like traps has been studied, for the information it can provide on the role played by point defects. Using the energy Et and trap density Nt as the only tunneling‐related fitting parameters, the behavior of the measured I(V) curves is well reproduced by our model over a wide current and temperature range. The very good agreement between simulations and experiments suggests that trap‐assisted forward tunneling is one of the most relevant contributions to the current flow below the optical turn‐on of the diode.