Title :
High-Frequency Modulation of GaAs/AlGaAs LEDs Using Ga-Doped ZnO Current Spreading Layers
Author :
Shang-Fu Chen ; He-Long Syu ; Chi-Chen Huang ; Yueh-Lin Lee ; Chong-Long Ho ; Meng-Chyi Wu
Author_Institution :
Inst. of Electron. Eng., Nat. Tsing Hua Univ., Hsinchu, Taiwan
Abstract :
In this letter, we report the high-frequency modulation of GaAs/AlGaAs near-infrared (NIR) light-emitting diodes (LEDs) with gallium-doped zinc oxide (GZO) prepared by atomic layer deposition as a current spreading layer. This report analyzes the effects of aperture area of the NIR LEDs on minority carrier lifetime and further investigates the required injection current to achieve the 3-dB frequency bandwidth of 100 MHz. At the same injection current density, the LEDs with different aperture areas always exhibit the same minority carrier lifetime, which is inversely proportional to the square root of current density. It means that the GZO layer plays a good current spreading in the lateral direction from the ohmic contact of NIR LEDs, which shows the lower contact resistance and lower forward voltage.
Keywords :
III-V semiconductors; aluminium alloys; atomic layer deposition; carrier lifetime; contact resistance; current density; frequency modulation; gallium arsenide; light emitting diodes; minority carriers; ohmic contacts; zinc compounds; GaAs-AlGaAs; NIR LED; atomic layer deposition; bandwidth 100 MHz; contact resistance; current spreading layer; gallium-doped zinc oxide current spreading layers; high-frequency modulation; injection current density; minority carrier lifetime; near-infrared light-emitting diodes; ohmic contact; Apertures; Bandwidth; Capacitance; Charge carrier lifetime; Current density; Light emitting diodes; Resistance; 3-dB modulation bandwidth; GaAs; LEDs; atomic layer deposition (ALD); gallium-doped ZnO (GZO); minority carrier lifetime;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2013.2291566
