Introduction
Luminescent material is a kind of materials that can absorb energy in a certain way and convert it into light radiation (non-equilibrium radiation). Luminescent materials are widely used in the semiconductor field due to their advantages of high luminous efficiency, good stability, low driving voltage and high brightness. In addition, light-emitting diode is a kind of semiconductor solid light-emitting device. It uses solid semiconductor chip as luminescent material and emits excess energy through the recombination of carriers in the semiconductor to cause photon emission, thereby emitting red, orange, yellow, green, cyan, blue, purple and white light.
Figure 1. The semiconductor devices
Mechanism
As a key component, luminescent materials play an important role in the performance of semiconductor devices. As for semiconductor luminescence, three band-structure-related luminescent mechanisms have been proposed.[1] As illustrated in Figure 2, when absorbing sufficiently high energies from the external environment, electrons will be promoted from the occupied valence band (VB) to the unoccupied conduction band (CB), resulting in the generation of mobile charge carriers (electrons (e) and holes (h)), which can also be artificially injected. Subsequently, emission occurs via inter-band transitions from the CB to VB (intrinsic luminescence), the CB to impurity states, impurity states to the VB, or impurity states to impurity states, all of which contribute to electron–hole recombination (dashed ellipse).
Figure 2. Luminescent mechanism for semiconductor devices. Inter-band electron hole recombination emission from (a) CB to VB; (b) CB to impurity states and impurity states to VB; (c) impurity states to impurity states.
What Can Alfa Chemistry Do?
Alfa Chemistry's technical R&D team has focused on the preparation and application of luminescent materials for many years, which has established long-term cooperative relationships with many well-known enterprises and research institutions. We have conducted research on various problems encountered by semiconductor devices, which can select the appropriate solution according to the customer's experimental purpose. If you want to know more about our products, please contact us.
Reference
- Su L. Inorganic 2D luminescent materials: structure, luminescence modulation, and applications. Adv. Optical Mater., 2020, 8(1): 1900978-1901018.
