Analysis of forward and reverse bias characteristics of DC LED

Semiconductor materials have a very interesting property, which is the so-called carriers; carriers are divided into two categories: one is electrons, which are negatively charged; the other is holes.

Semiconductor materials have a very interesting property, which is the so-called carriers. Carriers are divided into two categories: one is electrons, which are negatively charged; the other is holes, which are positively charged. The light-emitting principle of LCD is that the two types of carriers can combine under certain conditions, and the energy released is released in the form of photons to emit light.

也因此，依据材料的不同，电子和电洞所占有的能阶不同，也就是说电子和电洞的相对能阶高度差即是决定两载子所结合发出能量的高低，便可以产生具有不同能量的光子，藉此可以控制LED所发出光的波长，也就是光谱或颜色。

In most applications, LEDs are operated with direct current, which has the following characteristics:

Forward bias characteristics: When the DC current has enough positive voltage, the current of the LED will rise rapidly, and this current is called "forward bias current", and the voltage across the LED is called "forward bias voltage". If the voltage range is high and low, it means that the quality is abnormal, and generally the shorter the wavelength of the LED, the higher the voltage.

Reverse bias characteristic: As the name suggests, it is to give the LED a negative voltage, also known as "leakage voltage". Generally speaking, different LED materials will have their own reasonable voltage values. The reason for the poor reverse voltage characteristic is electrostatic discharge. This characteristic can also be used to evaluate the quality of this LED.