Coupled plasmonic-passivation luminescence enhancement in InGaN quantum wells with Ag/AlN capping

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Indium Gallium Nitride (InGaN) multi-quantum wells (MQWs) are crucial for optoelectronic devices.
• Enhancing radiative efficiency in InGaN MQWs is essential for device performance.
• Parasitic recombination channels can limit the efficiency of InGaN MQWs.

Purpose of the Study:

• To investigate the Ag/AlN metal/dielectric combination for enhancing InGaN MQW radiative efficiency.
• To elucidate the roles of passivation and plasmonic mechanisms in efficiency enhancement.
• To quantify the improvements in photoluminescence (PL) and spontaneous emission rates.

Main Methods:

• Steady-state and time-resolved photoluminescence (PL) measurements.
• Fabrication of InGaN MQW structures with Ag/AlN layers.
• Analysis of passivation and plasmonic effects separately.

Main Results:

• Aluminum Nitride (AlN) surface passivation effectively eliminated parasitic recombination channels.
• Ag layer addition resulted in 7.0-8.3× PL enhancements in the top QW.
• Spontaneous emission rates increased up to 8.1× due to resonant coupling to Ag surface plasmons.

Conclusions:

• Ag/AlN is a highly effective combination for boosting InGaN MQW radiative efficiency.
• The synergistic effects of AlN passivation and Ag plasmonics are crucial.
• Close proximity enabled by AlN passivation maximizes plasmonic enhancement.