Application Cases

Experiment Title: Application of Power Amplifiers in Driving Non-Carrier-Injected Micro-LEDs

Research Areas: Semiconductor Devices, Optoelectronic Devices, Micro-LEDs

Experiment Description:

1. Fabricated a non-carrier-injected micro-LED device using aluminum oxide as the insulating layer.

2. Utilized a signal generator to produce AC signals, which were amplified using an Aigtek power amplifier to drive the non-carrier-injected micro-LED, achieving a wide voltage operating window.

Test Objective:
To drive the non-carrier-injected micro-LED using a high-frequency AC high-voltage power supply and record its optoelectronic characteristics.

Test Equipment:
Signal generator, Aigtek ATA-61220 amplifier, oscilloscope, photomultiplier tube

Experimental Procedure:
Non-carrier-injected micro-LEDs were fabricated by depositing aluminum oxide insulating layers of varying thicknesses onto micro-LEDs via atomic layer deposition. A fixed-frequency AC high-voltage signal generated by a signal generator and amplified by a power amplifier was applied across the device to drive the non-carrier-injected micro-LED and achieve electroluminescence. By varying the driving voltage and frequency, the optoelectronic characteristics of the device were recorded using equipment such as an avalanche photomultiplier tube and an oscilloscope.

Test Results:
A working mode to enhance the brightness stability of micro-LEDs was demonstrated, and electroluminescence in non-carrier-injected mode under AC driving was verified. By adjusting the voltage and frequency of the AC power supply and optimizing the thickness of the dielectric layer, a wide operating voltage window for the micro-LED device was achieved, where the device brightness remained nearly constant within a specific voltage range. The results indicated that under 12 MHz frequency driving, the device current tended to saturate, and increasing the voltage only raised the maximum saturation current. Additionally, the device with a 15 nm thick aluminum oxide layer exhibited the largest operating voltage window (approximately 12 V) and the strongest brightness stability under voltage fluctuations.