激光剥离技术实现垂直结构GaN基LED

为改善GaN基发光二极管(Light-emitting diode,LED)的电学特性和提高其输出光功率,采用激光剥离技术,在KrF准分子激光器脉冲激光能量密度为400mJ/cm2的条件下,将GaN基LED从蓝宝石衬底剥离,结合金属熔融键合技术,在300℃中将GaN基LED转移至高电导率和高热导率的硅衬底,制备出了具有垂直结构的GaN基LED,并对其电学和光学特性进行了测试。结果表明:在110mA注入电流下,垂直结构器件的开启电压由普通结构的3.68V降低到了3.27V;在560mA注入电流下,器件输出光功率没有出现饱和现象;采用高电导率和高热导率的硅衬底能有效地改善GaN基LED的电学和光学特性。

Vertical GaN light-emitting diodes fabricated by laser lift-off technique

In order to improve the electrical characteristic and light output power of GaN-based light-emitting diodes(LEDs),GaN-based LEDs are separated from sapphire substrates by laser lift-off(LLO) technique using KrF excimer laser with 400mJ/cm2 energy density.The free-standing GaN-based LEDs are transferred to Si substrates by Sn/Au fusion bonding at 300℃,forming the vertical GaN-based LEDs on Si.The electrical and optical characteristics of the samples are investigated.The results show that the forward voltage of GaN-based LEDs on Si and on sapphire is 3.27V and 3.68V respectively at 110mA,and the output power of vertical GaN-based LEDs keeps increasing up to 560mA free of saturation because of the high electrical and thermal conductivity of Si substrates.