Photon upconversion in degenerately sulfur doped InP nanowires.

Area of Science:

• Semiconductor Nanowires
• Optoelectronics
• Solid State Physics

Background:

• Degenerately n-doped Indium Phosphide (InP) nanowires are crucial for optoelectronic applications.
• Understanding radiative recombination dynamics is key to optimizing device performance.
• Excitation energies relative to the Fermi level significantly impact carrier behavior.

Purpose of the Study:

• To investigate radiative recombination in n-doped InP nanowires under varying excitation conditions.
• To explore the phenomenon of photon upconversion in this system.
• To analyze the role of electron heating and hole scattering in recombination processes.

Main Methods:

• Photoluminescence spectroscopy was employed for excitation above and below the Fermi energy.
• Laser-induced electron heating was utilized to probe absorption mechanisms.
• Temperature-dependent measurements were performed to study scattering processes.

Main Results:

• Laser-induced electron heating was observed, enabling absorption below the Fermi energy.
• Photon upconversion was detected, attributed to the recombination of photo-excited holes with high momentum electrons.
• The temperature dependence of hole scattering to high |k|-values was measured.
• Hole relaxation via phonon scattering was observable in continuous wave excitation luminescence.

Conclusions:

• Radiative recombination in n-doped InP nanowires exhibits complex behavior influenced by excitation energy and electron temperature.
• Photon upconversion is a significant process in these nanowires, driven by hole scattering.
• Phonon scattering plays a measurable role in hole relaxation dynamics.