Different properties of GaN-based LED grown on Si(111) and transferred onto new substrate

Abstract

InGaN MQW LEDs, grown by metal-organic chemical vapor deposition (MOCVD) on Si(111) substrates, were successfully bonded and transferred onto new Si substrate. After chemical etching Si(111) substrate and inductively coupled plasma (ICP)etching the transferred LED film to Si-doped layer, a vertical structure GaN blue LEDs were then fabricated. The characteristics of the lateral structure LED (grown on Si) and the vertical structure LED (bonded on Si) were investigated. It shows the performance of vertical structure LEDs had obviously been improved compared to the lateral structure LEDs and the tensile stress in GaN layer of vertical structure LEDs is smaller than that in lateral structure LEDs.

Effects of reflector-induced interferences on light extraction of InGaN/GaN vertical light emitting diodes

“…And the distance between the active region and the metal reflector was confirmed by TEM. After growth, the flip-chip vertical structure devices were fabricated by a wafer bonding and film transfer process [1]. Firstly, 80 nm-Pt film was evaporated onto the surface of the as-grown sample acting as the p-electrode and reflector.…”

“…Much attention has recently been paid to InGaN/GaN vertical structure light emitting diodes (VLEDs) as it shows higher chip utilization percentage, better current spreading, and lower series resistance than those of the lateral structure LEDs [1][2][3]. However, the inherent limitation of light extraction efficiency (C ext ) that only those light emitting into the escape cone given by the critical angle of the total reflection (sin y c ¼n ambient /n GaN ) can be extracted still exist [4,5].…”

Structural effects of field emission from GaN nanofilms on SiC substrates

“…31 The lattice mismatch between GaN and the SiC substrate is small so the stress resulting from lattice mismatch can be neglected, 32 and was not considered in the analysis of peak shift. Figure 7 shows that the peak positions move to larger 2h as the thickness of GaN NFs increases from 10 to 15 to 50 nm (i.e., samples A, B, and E, respectively), which originates from the tensile stress in GaN NFs 20,33,34 caused by the small size of the GaN nanoparticles, the thermal mismatch and the defects produced by the nonstoichiometric ratio of Ga and N atoms. 30,31 For GaN NFs with a thickness of 20 and 30 nm (samples C and D, respectively), the diffraction angle moves to smaller 2h, which results from the compressive stress produced by the defects caused by the nonstoichiometric ratio of Ga and N atoms.…”

High-speed Visible Light Communication Systems Based on Si-substrate LEDs with Multiple Superlattice Interlayers

“…Consequently, the limitation motivates the development of the Si substrate for LEDs growth. It not only has a lower cost, a larger size, the good thermal and electrical conductivity [12], but also easily realizes the vertical structure by a simple wet chemical etching technology to lift off the GaN film from the Si substrate. In contrast, the sapphire-substrate LED needs laser lift-off technology, which will inevitably damage the crystal quality [13].…”