Quaternary ultraviolet AlInGaN MQW laser diode performance using quaternary AlInGaN electron blocking layer

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Ultraviolet (UV) laser diodes (LDs) are crucial for various applications.
• Electron-blocking layers (EBLs) are essential components in LDs to improve efficiency.
• Polarization effects in III-nitride materials can significantly impact device performance.

Purpose of the Study:

• To investigate the effect of a polarization-matched Al(0.25)In(0.08)Ga(0.67)N EBL on the optical performance of UV Al(0.08)In(0.08)Ga(0.84)N/Al(0.1)In(0.01)Ga(0.84)N multi-quantum well (MQW) LDs.
• To compare the performance of a quaternary Al(0.25)In(0.08)Ga(0.67)N EBL with a ternary Al(0.3)Ga(0.7)N EBL.
• To determine the optimal thickness of the Al(0.25)In(0.08)Ga(0.67)N EBL for enhanced LD performance.

Main Methods:

• Device simulation using the Integrated System Engineering Technical Computer Aided design (ISE TCAD) program.
• Modeling of carrier transport via drift-diffusion.
• Analysis of optical gain and losses.
• Comparison of LDs with different EBL materials and thicknesses.

Main Results:

• The polarization-matched Al(0.25)In(0.08)Ga(0.67)N EBL confines electrons more effectively within the quantum well compared to the ternary Al(0.3)Ga(0.7)N EBL.
• LDs utilizing the Al(0.25)In(0.08)Ga(0.67)N EBL exhibited a lower threshold current and higher optical intensity.
• Optimal performance, including lower threshold current, high slope efficiency, high output power, and high differential quantum efficiency (DQE), was achieved with an Al(0.25)In(0.08)Ga(0.67)N EBL thickness of 0.25 µm at room temperature.

Conclusions:

• The polarization-matched quaternary Al(0.25)In(0.08)Ga(0.67)N EBL is a superior choice for improving the optical performance of UV MQW LDs.
• Optimizing EBL thickness is critical for maximizing LD efficiency and output characteristics.
• This research provides valuable insights for the design and fabrication of high-performance UV optoelectronic devices.