Camilla Southern Charms
Camilla Southern Charms
camilla southern charms
camilla southern charmsA semiconductor light emitting device such as a light emitting diode (LED) includes a first conductive semiconductor layer; a second conductive semiconductor layer which has a wider bandgap than the first conductive semiconductor layer and which is formed on the first conductive semiconductor layer; and a light emitting layer which is formed on the second conductive semiconductor layer and which has a narrower bandgap than the second conductive semiconductor layer. The semiconductor light emitting device is a type of a semiconductor device that generates light when electricity is applied thereto.
Semiconductor devices such as light emitting diodes or laser diodes (LDs) using Group III-V or II-VI semiconductor are being widely used because of their low costs, long lifetimes, and high efficiency.
In case of fabricating an LED using InGaN-based material, a method of directly depositing InGaN on a substrate is widely adopted. However, there is a problem with this method. That is, since a light emitting layer is formed to be small in thickness, the light emitting layer may be damaged during depositing InGaN on the substrate.
Therefore, the light emitting layer is typically formed on the second conductive semiconductor layer, which has a wider bandgap than the first conductive semiconductor layer, so as to prevent the light emitting layer from being damaged by the deposition. However, the light emitting layer, which is formed on the second conductive semiconductor layer, is electrically connected to the first conductive semiconductor layer, which is formed in the upper part of the light emitting layer, through the second conductive semiconductor layer. Therefore, when applying a constant current to the first conductive semiconductor layer through the second conductive semiconductor layer, the current flowing to the light emitting layer through the second conductive semiconductor layer may be larger than the current flowing through the first conductive semiconductor layer. In this case, the light emission amount of the light emitting layer is increased, but the current flowing through the first conductive semiconductor layer is decreased. Accordingly, the brightness of light generated by the light emitting layer may be decreased.
In addition, in case of using ZnO, which is a p-type semiconductor material, as a second conductive semiconductor layer, a transparent p-type semiconductor layer is used as the light emitting layer. However, since the light emitting layer is a light