Electrical-efficiency analysis of GaN-based light-emitting diodes with interdigitated-mesa geometry

• Published in: Journal of electronic materials Vol. 32; no. 5; pp. 312 - 315
• Main Authors: TING, Yi-Sheng, CHEN, Chii-Chang, SHEU, Jinn-Kong, CHI, Gou-Chung, HSU, Jung-Tsung
• Format: Journal Article
• Language: English
• Published: New York, NY Institute of Electrical and Electronics Engineers 01.05.2003; Springer Nature B.V
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Optoelectronic devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Performance evaluation; GaN-based LEDs; Binary compound; efficiency; integrated-mesa geometry; Optoelectronic device; MESA technology; Gallium nitride; Light emitting diode
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-003-0150-y

We propose a novel method to analyze the current-voltage (I-V) characteristics of GaN-based light-emitting diodes (LEDs) with different p-type electrode-mesa geometries. The electrical efficiency is analyzed by calculating the electric field under the quasi-coplanar electrodes of GaN-based LEDs. The experimental results for GaN-based LEDs of chip sizes of 350 x 350 *mm2 and 1,000 x 1,000 *mm2 with interdigitated fingers are compared. A good agreement is obtained between the experimental and theoretical electrical efficiency of the GaN LEDs with a chip size of 1,000 x 1,000 *mm2. The current-crowding effect is analyzed by measuring the electroluminescence spectra of the devices. The result indicates that the current-crowding effect is largely reduced by increasing the number of interdigitated fingers. The electrical efficiency of a LED with a chip size of 1,000 x 1,000 *mm2 can be also enhanced by increasing the number of interdigitated fingers, showing the advantages of GaN LED with interdigitated-mesa geometries.