Si-doped In _0.23Ga _0.77N/GaN short-period superlattice tunneling contact layer used on InGaN/GaN laser diode

Si-doped n ⁺-In _0.23Ga _0.77N/GaN short-period super-period superlattice (SPS) tunneling contact layer were used on InGaN/GaN multiple-quantum-well laser diode (LD) structures which were grown by metal-organic chemical vapor deposition (MOCVD). The n ⁺-In _0.23Ga _0.77N/GaN SPS was used to instead of the p-type GaN as a top contact layer. The lower forward voltages, smaller series resistances, and lower threshold current of the LD with SPS contact layer were achieved. On the other hand, the LD with an SPS layer exhibited a longer lasing duration than that of LD without an SPS layer under pulse operation. When the widths of input pulse were lengthened from 300 ns to 2 s, the lasing duration of the LD with Pt contact was three times longer than that of the LD with Ni/Au contact. Therefore, one would like to conclude that nitride-based LDs with an SPS tunneling contact layer will significantly reduce the contact resistance and increase the thermal stability of the device reliability.