High current gain transistor laser.

Area of Science:

• Optoelectronics
• Semiconductor Devices
• Quantum Electronics

Background:

• Transistor lasers (TLs) integrate transistor and laser functionalities.
• Existing TL designs suffer from low current gain due to trade-offs with light emission.

Purpose of the Study:

• To propose and numerically investigate a novel TL design to overcome the low current gain limitation.
• To enhance the current gain and reduce nonradiative recombination in TLs.

Main Methods:

• Introduction of an n-doped Indium Phosphide (InP) layer into the emitter ridge of the TL.
• Numerical simulations to analyze charge carrier flow and device performance.
• Analysis of current gain and defect recombination effects.

Main Results:

• The novel design facilitates the formation of a hole-selective current aperture in the emitter ridge.
• Achieved a common emitter current gain as high as 143.3, over 15 times greater than conventional TLs.
• Demonstrated significant reduction in nonradiative recombination due to confined hole flow.

Conclusions:

• The proposed n-doped InP layer in the emitter ridge is an effective strategy for enhancing TL current gain.
• This design improvement addresses a key limitation in current transistor laser technology.
• The findings pave the way for more efficient and higher-performance optoelectronic devices.