Experiment name:

Research on the photoelectric characteristics of non-conductor contact μLED devices

Research direction: AC LED driver, semiconductor device

Experiment content:

According to the non-conductor contact μLED model, the corresponding device is prepared. The second is to study the frequency-voltage, current-voltage, luminous intensity and other photoelectric characteristics of the μLED with this new structure under the AC signal drive.

      GaN-based micro-light-emitting diodes (μLEDs) have outstanding advantages in ultra-high-resolution displays, micro-displays, visible light communications, and solid-state lighting. The working mechanism of the traditional μLED is: when a forward voltage is applied, holes and electrons are injected into the multiple quantum wells from the p-region and the n-region to radiate and emit light. Under the forward bias, continuous electrons and holes are injected from the external electrode, resulting in continuous electroluminescence.

Testing purposes:

A non-conductor contact μLED model is established and its working mechanism is revealed, which provides theoretical guidance for improving the structure of μLED devices and optimizing the working mode.

Test Equipment:

Non-conductor contact μLED device, signal generator, power amplifier, optical power meter, avalanche photodetector, oscilloscope

Amplifier model: ATA-122D power amplifier

experiment procedure:  

Generate voltage signals of different frequencies through a signal generator, amplify and output them through a power amplifier, and apply them to a non-conductor contact μLED device. Use an oscilloscope to test its electrical characteristics, and an optical power meter and avalanche photodetector to test its electroluminescence characteristic.

Test Results:

Driven by an AC electric field, the μLED can be lit "wirelessly" without external charge injection.

1.A working model of NEC&NCI mode related to the periodic oscillation of carriers under the action of an alternating electric field is proposed, and the high optical power density is achieved by using a "carrier pump", which is further verified by experiments.

2.The self-protection mechanism of the "device in capacitor" is briefly discussed, that is, the μLED device of this structure can work normally under high-voltage drive to prevent electrical breakdown.

3.The effectiveness of the amplifier in this experiment: This device is the core device in this experiment, providing the adjustment function of the driving signal

Reasons for choosing this power amplifier: The equipment has high performance and the parameters meet the requirements (differential output, higher voltage amplitude, larger frequency range)