Major carrier in the N-type semiconductor

Major carrier in the N-type semiconductor, electronic, and P-type semiconductor, the main carrier is a hole, due to the movement of the charge, the depletion layer on both sides of the accumulation of charge in the internal formation of a N region points to a self-built electric field of the P region to prevent the hole continues to spread. When the incident light irradiation to the PN junction, depletion layer, it will cause the electrons absorb the photon energy, the transition to the conduction band, the formation can be conductive electron-hole pairs. More management work should be done in the production month of Laser Pointer .
Electrons and holes generated by light irradiation called photo-carrier; the role of self-built electric field, directed movement, in which holes along the field direction of the P region movement, electronic reverse electric field direction N district sports (they form the electric field self-built electric field weakened) to form a photocurrent. Incident light, the stronger the greater the photocurrent, which the optical signals into electrical signals, precisely because the photocurrent is enhanced with the enhancement of the incident if the incident light is too strong, so that the photocurrent increases to exceed the limits of PIN it will burn out the PIN diode and optical receiver manual clearly defines the upper limit of the input optical power, if you can not determine the optical power of the input light must not PIN docking to prevent burn out the PIN diode. The price of our Laser Pointer has the obvious advantage.
If both ends of the PN junction with reverse voltage, the applied electric field direction and self-built electric field within the depletion layer, the easier the movement of light generated carriers to improve the intensity of the light detector of weak exploration. In fact, in the absence of irradiation, also a small amount of current, which is due to the directional movement of the holes in the P-type semiconductor, electronics, and N-type semiconductor under reverse bias due to this current known as dark current, the existence of the dark current of the photodetector noise sources. Backlight detector is used for automatic power control devices, in order to ensure the accuracy of power control, the photodetector have the following characteristics: high enough level corresponding the operating wavelength range, that is back on the operating wavelength range to light. The advantage of Laser Pointer price has drawn a lot of attention of more customers.