GaN substrate and GaN homo-epitaxy for LEDs: Progress and challenges<xref ref-type="fn" rid="cpb150941fn1">*</xref>

GaN substrate and GaN homo-epitaxy for LEDs: Progress and challenges*

Wu Jie-Jun, Wang Kun, Yu Tong-Jun†, Zhang Guo-Yi

Schematic drawings of (a) vertical type HVPE system; (b) pulsed flow modulation method, in which 20-s long pulses of the NH3 flow was modulated between high and low flow rate periodically.^{[ 35 ]}