11/14/2020 · We also consider the self-absorption to the DUV photons by the absorptive material with a lower energy band gap, such that we set the absorption coefficient of the p-GaN to 1.45 × 10 7 m ?1 …
1/1/1999 · The mesh p-GaN/ITO DUV LED showed an output power of 12% higher than that from the conventional DUV LED due to the lower light absorption at 280 nm.
FIGURE 1 A, Normalized optical absorption spectra of n-SnO 2, p-GaN and -GaN/ 2 heterostructure. Inset is the (? h?)2 vs plots for n-SnO 2 and p-GaN. B, Photoluminescence (PL) spectra of n-SnO 2, p-GaN and p-GaN/n-SnO 2 heterostructure at room temperature. C and D, Scanning electron microscope (SEM) images of p-GaN at different magnifications.
4/16/2004 · The virgin sample did not show any strong defect absorption bands. In contrast, the implanted samples showed very strong absorption in the extrinsic region. Figure 6 shows the squared absorption coefficient ? 2 versus photon energy . Three defect bands can be clearly seen: the A1 defect band with the threshold energy of 1.3–1.35 eV, the A2 …
However, p-GaN has a very high absorption coefficient in the DUV range, which means LEE can be significantly reduced. If a PhC can alleviate this absorption and increase the reflectance, the EQE can be increased. We carried out a further investigation in which a p-GaN layer was inserted into the p-AlGaN PhC structure as shown in Fig. 1(c). Fig.
9/1/2001 · The maximum value of absorption coefficient in our samples is about 10 4 cm ?1 (at h?=3.5 eV). It is known that in high quality GaN layers the absorption coefficient reach the value of about 10 5 cm ?1. Taking into account this fact and the existence in our samples of two spectral intervals with different Urbach energies we propose a simple model of GaN epitaxial film.
1/1/2016 · As we know, in the major AlGaN DUV LEDs, the p-GaN is often used as a p-type contact layer, so the light extraction efficiency is significantly reduced by internal absorption and total internal reflection owing to the high absorption coefficient and refractive index of GaN in DUV region .
