The Effect of Interdigitated Layout Design on the Improvement of Optical and GHz
Modulation Bandwidth of Tilted-Charge Light-Emitting Diodes

Mong-Kai Wu1, Chao-Hsin Wu1, Gabriel Walter2, Milton Feng1
Poh Lian Lam2, Teyo Chin2, Azim Mohammad2
1Department of Electrical and Computer Engineering, University of Illinois
Micro and Nanotechnology Laboratory, 208 N. Wright Street, Urbana, IL 61801
2Quantum Electro Opto Systeems (QEOS) Sdn. Bhd, Melaka, Malaysia
Phone: (217)244-3662, e-mail:

Keywords: Light-emitting Transistor, tiled-charge lightemitting


To enhance the optical output and modulation bandwidth, the interdigitated tilted-charge light-emitting diodes with different geometries are fabricated and measured. The optical output scales with the emitter area only when the emitter lateral-feeding width is less than 5 m. When emitter size exceeds certain width, the light output is more dependent on the peripheral effect. Increasing the distance between the bottom contact and emitter mesa can also improve the light output by 1.8 times. However, it limits the optical modulation bandwidth due to the increasing resistance effect. The fast spontaneous modulation of tilted-charge LED is also demonstrated by the 3 Gb/s eye diagram.

Paper 13.11.pdf